Dont cast away const needlessly. Found by gcc48 -Wcast-qual.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163325 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/HeaderMap.cpp b/lib/Lex/HeaderMap.cpp
index bbfc1df..7dc0491 100644
--- a/lib/Lex/HeaderMap.cpp
+++ b/lib/Lex/HeaderMap.cpp
@@ -144,7 +144,7 @@
                                         sizeof(HMapHeader));
 
   const HMapBucket *BucketPtr = BucketArray+BucketNo;
-  if ((char*)(BucketPtr+1) > FileBuffer->getBufferEnd()) {
+  if ((const char*)(BucketPtr+1) > FileBuffer->getBufferEnd()) {
     Result.Prefix = 0;
     Result.Suffix = 0;
     return Result;  // Invalid buffer, corrupt hmap.