Simplify users of StringRef::{l,r}trim (clang) (NFC)

r260925 introduced a version of the *trim methods which is preferable
when trimming a single kind of character. Update all users in clang.

llvm-svn: 260927
diff --git a/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
index 504b8b3..a25f3e0 100644
--- a/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
@@ -1000,7 +1000,7 @@
     return;
 
   StringRef Comment =
-      StringRef(Result.getLiteralData(), Result.getLength()).trim("\"");
+      StringRef(Result.getLiteralData(), Result.getLength()).trim('"');
 
   if ((Comment.trim().size() == 0 && Comment.size() > 0) || // Is Whitespace
       Comment.empty()) {