[llvm] [llvm-objcopy][test] Improve install-name-tool -o tests (NFC) (PR #201883)

[James Henderson via llvm-commits]

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@@ -2,19 +2,13 @@
 
 # RUN: yaml2obj %s -o %t
 
-## Writing to a separate file with -o:
-# RUN: llvm-install-name-tool -id /usr/lib/short-id -o %t.short %t
-# RUN: llvm-objdump -p %t | FileCheck %s --check-prefix=INPUT --implicit-check-not='name /usr/lib/short-id'
-# RUN: llvm-objdump -p %t.short | FileCheck %s --check-prefix=SHORT --implicit-check-not='name /usr/lib/original-id'
+## Writing separate files produces the same output as editing in place
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jh7370 wrote:

```suggestion
## Writing separate files produces the same output as editing in place.
```

https://github.com/llvm/llvm-project/pull/201883