[LoopSimplifyCFG] Remove Extra Redirection From Test

This test would redirect stderr into /dev/null for no reason. Update it
to better match the tests around it. This extra indirection also caused
the test to not play nicely with lit's internal shell with profcheck
enabled.

Related to llvm#162966.

Author: boomanaiden154

llvm/test/Transforms/LoopSimplifyCFG/pr117537.ll

@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
-; RUN: opt -S -passes='print<scalar-evolution>,loop-mssa(licm,loop-simplifycfg,loop-predication)' -verify-scev < %s 2>/dev/null | FileCheck %s
+; RUN: opt -S -passes='print<scalar-evolution>,loop-mssa(licm,loop-simplifycfg,loop-predication)' -verify-scev < %s | FileCheck %s
 
 ; Make sure we don't assert due to insufficient SCEV invalidation.