nfsd: Add DEALLOCATE support

DEALLOCATE only returns a status value, meaning we can use the noop()
xdr encoder to reply to the client.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index a60cff8..0622d4f 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1624,7 +1624,7 @@
 	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
 	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_notsupp,
 	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
 	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
 	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
 	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,