RDMA/rtrs-srv: Clean up the code in __rtrs_srv_change_state

No need to use double switch to check the change of state everywhere,
let's change them to "if" to reduce size.

Link: https://lore.kernel.org/r/20210528113018.52290-5-jinpu.wang@ionos.comSigned-off-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/ulp/rtrs/rtrs-srv.c

@@ -77,32 +77,17 @@ static bool __rtrs_srv_change_state(struct rtrs_srv_sess *sess,
 	old_state = sess->state;
 	switch (new_state) {
 	case RTRS_SRV_CONNECTED:
-		switch (old_state) {
-		case RTRS_SRV_CONNECTING:
+		if (old_state == RTRS_SRV_CONNECTING)
 			changed = true;
-			fallthrough;
-		default:
-			break;
-		}
 		break;
 	case RTRS_SRV_CLOSING:
-		switch (old_state) {
-		case RTRS_SRV_CONNECTING:
-		case RTRS_SRV_CONNECTED:
+		if (old_state == RTRS_SRV_CONNECTING ||
+		    old_state == RTRS_SRV_CONNECTED)
 			changed = true;
-			fallthrough;
-		default:
-			break;
-		}
 		break;
 	case RTRS_SRV_CLOSED:
-		switch (old_state) {
-		case RTRS_SRV_CLOSING:
+		if (old_state == RTRS_SRV_CLOSING)
 			changed = true;
-			fallthrough;
-		default:
-			break;
-		}
 		break;
 	default:
 		break;