[llvm] [VPlan] Format some print forms.NFC (PR #144644)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/19955

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: Transforms/LoopVectorize/RISCV/riscv-vector-reverse.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/opt -passes=loop-vectorize,dce,instcombine -mtriple riscv64-linux-gnu    -mattr=+v -debug-only=loop-vectorize,vplan -scalable-vectorization=on    -riscv-v-vector-bits-min=128 -disable-output < /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/riscv-vector-reverse.ll 2>&1 | /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/riscv-vector-reverse.ll # RUN: at line 9
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/opt -passes=loop-vectorize,dce,instcombine -mtriple riscv64-linux-gnu -mattr=+v -debug-only=loop-vectorize,vplan -scalable-vectorization=on -riscv-v-vector-bits-min=128 -disable-output
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/riscv-vector-reverse.ll
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/riscv-vector-reverse.ll:277:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: LV: vectorizing VPBB:ir-bb<for.body.preheader> in BB:for.body.preheader
              ^
<stdin>:264:2: note: scanning from here
}
 ^
<stdin>:265:1: note: possible intended match here
LV: vectorizing VPBB: ir-bb<for.body.preheader> in BB: for.body.preheader
^
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/riscv-vector-reverse.ll:686:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: LV: vectorizing VPBB:ir-bb<for.body.preheader> in BB:for.body.preheader
              ^
<stdin>:645:2: note: scanning from here
}
 ^
<stdin>:646:1: note: possible intended match here
LV: vectorizing VPBB: ir-bb<for.body.preheader> in BB: for.body.preheader
^

Input file: <stdin>
Check file: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/riscv-vector-reverse.ll

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            1:  
            2: LV: Checking a loop in 'vector_reverse_i64' from <stdin> 
label:14'0                            ^~~~~~~~~~~~~~~~~~~~
label:14'1                            ^~~~~~~~~~~~~~~~~~~~
            3: LV: Loop hints: force=enabled width=vscale x 4 interleave=0 
next:15        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            4: LV: Found a loop: for.body 
next:16        ^~~~~~~~~~~~~~~~~~~~~~~~~~
            5: LV: Found an induction variable. 
next:17        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            6: LV: Found an induction variable. 
next:18        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            7: LV: Did not find one integer induction var. 
next:19        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            8: LV: We can vectorize this loop (with a runtime bound check)! 
next:20        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...

```

</details>

https://github.com/llvm/llvm-project/pull/144644