Added lock in ifr ioctl calls.

net/netdev/netdev_ioctl.c

@@ -641,6 +641,8 @@ static int netdev_ifr_ioctl(FAR struct socket *psock, int cmd,
 
   ninfo("cmd: %d\n", cmd);
 
+  net_lock();
+
   /* Execute the command */
 
   switch (cmd)
@@ -1139,6 +1141,8 @@ static int netdev_ifr_ioctl(FAR struct socket *psock, int cmd,
         break;
     }
 
+  net_unlock();
+
   return ret;
 }