rds: Fix improper gfp_t usage.

>> net/rds/ib_recv.c:382:28: sparse: incorrect type in initializer (different base types)
   net/rds/ib_recv.c:382:28:    expected int [signed] can_wait
   net/rds/ib_recv.c:382:28:    got restricted gfp_t
   net/rds/ib_recv.c:828:23: sparse: cast to restricted __le64
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/rds/ib_recv.c

@@ -379,7 +379,7 @@ void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp)
 	struct ib_recv_wr *failed_wr;
 	unsigned int posted = 0;
 	int ret = 0;
-	int can_wait = gfp & __GFP_WAIT;
+	bool can_wait = !!(gfp & __GFP_WAIT);
 	u32 pos;
 
 	/* the goal here is to just make sure that someone, somewhere