[OpenMP] NFC fix compilation warning about unused variable

lib/Sema/SemaOpenMP.cpp:9243:13: warning: variable ‘IsRightMostExpression’ set but not used

llvm-svn: 263202
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index bc15c02..94eb697 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -9240,8 +9240,7 @@
   bool AllowUnitySizeArraySection = true;
   bool AllowWholeSizeArraySection = true;
 
-  for (bool IsRightMostExpression = true; !RelevantExpr;
-       IsRightMostExpression = false) {
+  while (!RelevantExpr) {
     E = E->IgnoreParenImpCasts();
 
     if (auto *CurE = dyn_cast<DeclRefExpr>(E)) {