Fix gcc -Wparentheses warning.

llvm-svn: 201840
diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 08f19fb..efc08aa 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -306,7 +306,7 @@
     return 0;
   }
 
-  assert(openFile || !F && "undesired open file");
+  assert((openFile || !F) && "undesired open file");
 
   // It exists.  See if we have already opened a file with the same inode.
   // This occurs when one dir is symlinked to another, for example.