nfs: fix unchecked value

Return value of "decode_attr_bitmap()" was not checked;

Signed-off-by: Roman Borisov <ext-roman.borisov@nokia.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 7131c76..bd2101d 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2687,7 +2687,10 @@
 static int decode_attr_supported(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *bitmask)
 {
 	if (likely(bitmap[0] & FATTR4_WORD0_SUPPORTED_ATTRS)) {
-		decode_attr_bitmap(xdr, bitmask);
+		int ret;
+		ret = decode_attr_bitmap(xdr, bitmask);
+		if (unlikely(ret < 0))
+			return ret;
 		bitmap[0] &= ~FATTR4_WORD0_SUPPORTED_ATTRS;
 	} else
 		bitmask[0] = bitmask[1] = 0;