nfsd: add missing FATTR4_WORD2_CLONE_BLKSIZE from supported attributes

RFC 7862 Section 4.1.2 says that if the server supports CLONE it MUST
support clone_blksize attribute.

Fixes: d6ca7d2 ("NFSD: Implement FATTR4_CLONE_BLKSIZE attribute")
Cc: stable@vger.kernel.org
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Author: Olga Kornievskaia

fs/nfsd/nfsd.h

@@ -458,6 +458,7 @@ enum {
 #define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
 	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | \
 	FATTR4_WORD2_MODE_UMASK | \
+	FATTR4_WORD2_CLONE_BLKSIZE | \
 	NFSD4_2_SECURITY_ATTRS | \
 	FATTR4_WORD2_XATTR_SUPPORT | \
 	FATTR4_WORD2_TIME_DELEG_ACCESS | \