sockets: Remove unreachable break statements in event_callback

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Dirk Ziegelmeier <dirk@ziegelmeier.net>

src/api/sockets.c

@@ -2120,7 +2120,6 @@ event_callback(struct netconn *conn, enum netconn_evt evt, u16_t len)
     case NETCONN_EVT_RCVMINUS:
       sock->rcvevent--;
       goto no_select_wakeup;
-      break;
     case NETCONN_EVT_SENDPLUS:
       if (sock->sendevent) {
         goto no_select_wakeup;
@@ -2130,7 +2129,6 @@ event_callback(struct netconn *conn, enum netconn_evt evt, u16_t len)
     case NETCONN_EVT_SENDMINUS:
       sock->sendevent = 0;
       goto no_select_wakeup;
-      break;
     case NETCONN_EVT_ERROR:
       sock->errevent = 1;
       break;