rds: Remove redundant assignment to nr_sig

Variable nr_sig is being assigned a value however the assignment is
never read, so this redundant assignment can be removed.

Cleans up the following clang-analyzer warning:

net/rds/ib_send.c:297:2: warning: Value stored to 'nr_sig' is never read
[clang-analyzer-deadcode.DeadStores].
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/rds/ib_send.c

@@ -294,7 +294,6 @@ void rds_ib_send_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
 
 	rds_ib_ring_free(&ic->i_send_ring, completed);
 	rds_ib_sub_signaled(ic, nr_sig);
-	nr_sig = 0;
 
 	if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
 	    test_bit(0, &conn->c_map_queued))