Fix a typo in webkit.NoUncountedMemberChecker. (#91402)

Co-authored-by: Brianna Fan <[email protected]>

Author: rniwa

clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp

@@ -34,7 +34,7 @@ class NoUncountedMemberChecker
 public:
   NoUncountedMemberChecker()
       : Bug(this,
-            "Member variable is a raw-poiner/reference to reference-countable "
+            "Member variable is a raw-pointer/reference to reference-countable "
             "type",
             "WebKit coding guidelines") {}