cifs: trivial comment fix for cifs_invalidate_mapping

Only the callers check whether the invalid_mapping flag is set and not
cifs_invalidate_mapping().

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index ff7d299..669298f 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1670,7 +1670,9 @@
 	return false;
 }
 
-/* check invalid_mapping flag and zap the cache if it's set */
+/*
+ * Zap the cache. Called when invalid_mapping flag is set.
+ */
 static void
 cifs_invalidate_mapping(struct inode *inode)
 {