[polly] [polly][test] Fix filecheck annotation typos (PR #94211)

[via llvm-commits]

klensy wrote:

No tests magically fixed itself, sad:
```
Failed Tests (7):
--
  | Polly :: CodeGen/OpenMP/single_loop.ll
  | Polly :: CodeGen/conflict-between-loop-invariant-code-hosting-and-escape-map-computation.ll
  | Polly :: CodeGen/entry_with_trivial_phi.ll
  | Polly :: CodeGen/inner_scev_sdiv_1.ll
  | Polly :: CodeGen/multidim_alias_check.ll
  | Polly :: ScheduleOptimizer/ManualOptimization/unroll_double.ll
  | Polly :: ScopInfo/constant_start_integer.ll
```

https://github.com/llvm/llvm-project/pull/94211