fix warning with gcc 4.1 (ptr to bool convertion)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@51324 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicObjCFoundationChecks.cpp b/lib/Analysis/BasicObjCFoundationChecks.cpp
index 8e8feec..1694380 100644
--- a/lib/Analysis/BasicObjCFoundationChecks.cpp
+++ b/lib/Analysis/BasicObjCFoundationChecks.cpp
@@ -160,7 +160,7 @@
   ObjCInterfaceType* ReceiverType = GetReceiverType(ME);
   
   if (!ReceiverType)
-    return NULL;
+    return false;
   
   const char* name = ReceiverType->getDecl()->getIdentifier()->getName();
   
@@ -177,7 +177,7 @@
   if (isNSString(ReceiverType, name))
     return AuditNSString(N, ME);
 
-  return false;  
+  return false;
 }
 
 static inline bool isNil(RVal X) {