nfsd: git rid of nfs4_cb_null_ops declaration

There's no use for nfs4_cb_null_ops's declaration in fs/nfsd/nfs4callback.c
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs4callback.c

@@ -53,9 +53,6 @@
 #define NFSPROC4_CB_NULL 0
 #define NFSPROC4_CB_COMPOUND 1
 
-/* declarations */
-static const struct rpc_call_ops nfs4_cb_null_ops;
-
 /* Index of predefined Linux callback client operations */
 
 enum {