netutils/rexecd: fix rpname mismatch with rexec when using AF_RPMSG

When using AF_RPMSG (-r option), rexecd was setting the rp_name
to the raw port number, while rexec was using htons(port). This
caused a mismatch where rexec couldn't connect to rexecd.

This commit fixes the issue by applying htons() to REXECD_PORT
when setting rp_name in the AF_RPMSG case, making it consistent
with the rexec client implementation.

Signed-off-by: fangpeina <fangpeina@xiaomi.com>

Author: fangpeina

netutils/rexecd/rexecd.c

@@ -223,7 +223,7 @@ int main(int argc, FAR char **argv)
       case AF_RPMSG:
         ((FAR struct sockaddr_rpmsg *)&addr)->rp_family = AF_RPMSG;
         snprintf(((FAR struct sockaddr_rpmsg *)&addr)->rp_name,
-                 RPMSG_SOCKET_NAME_SIZE, "%d", REXECD_PORT);
+                 RPMSG_SOCKET_NAME_SIZE, "%d", htons(REXECD_PORT));
         ret = sizeof(struct sockaddr_rpmsg);
     }