IB/mlx4: Remove unnecessary parentheses

Clang warns when more than one set of parentheses are used in single
conditional statements.

drivers/infiniband/hw/mlx4/mcg.c:676:16: warning: equality comparison
with extraneous parentheses [-Wparentheses-equality]
                        if ((method == IB_MGMT_METHOD_GET_RESP)) {
                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/infiniband/hw/mlx4/mcg.c:676:16: note: remove extraneous
parentheses around the comparison to silence this warning
                        if ((method == IB_MGMT_METHOD_GET_RESP)) {
                            ~       ^                         ~
drivers/infiniband/hw/mlx4/mcg.c:676:16: note: use '=' to turn this
equality comparison into an assignment
                        if ((method == IB_MGMT_METHOD_GET_RESP)) {
                                    ^~
                                    =

Remove the unnecessary parentheses to silence this warning.
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx4/mcg.c

@@ -673,7 +673,7 @@ static void mlx4_ib_mcg_work_handler(struct work_struct *work)
 			if (!list_empty(&group->pending_list))
 				req = list_first_entry(&group->pending_list,
 						struct mcast_req, group_list);
-			if ((method == IB_MGMT_METHOD_GET_RESP)) {
+			if (method == IB_MGMT_METHOD_GET_RESP) {
 					if (req) {
 						send_reply_to_slave(req->func, group, &req->sa_mad, status);
 						--group->func[req->func].num_pend_reqs;