NFSv3: fix sync_retry in direct i/o NFS

 Only do a sync_retry if the memcmp failed.
Signed-off-by: NDirk Mueller <dmueller@suse.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/direct.c

@@ -481,7 +481,7 @@ static ssize_t nfs_direct_write_seg(struct inode *inode,
 		if (wdata->verf.committed != NFS_FILE_SYNC) {
 			need_commit = 1;
 			if (memcmp(&first_verf.verifier, &wdata->verf.verifier,
-					sizeof(first_verf.verifier)));
+					sizeof(first_verf.verifier)))
 				goto sync_retry;
 		}