RDS: Refill recv ring directly from tasklet

Performance is better if we use allocations that don't block
to refill the receive ring. Since the whole reason we were
kicking out to the worker thread was so we could do blocking
allocs, we no longer need to do this.

Remove gfp params from rds_ib_recv_refill(); we always use
GFP_NOWAIT.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

net/rds/ib_cm.c

@@ -135,7 +135,7 @@ void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_even
 	rds_ib_recv_init_ring(ic);
 	/* Post receive buffers - as a side effect, this will update
 	 * the posted credit count. */
-	rds_ib_recv_refill(conn, GFP_KERNEL, GFP_HIGHUSER, 1);
+	rds_ib_recv_refill(conn, 1);
 
 	/* Tune RNR behavior */
 	rds_ib_tune_rnr(ic, &qp_attr);