Fix code warning.

Change-Id: Ib11fb49f528d3688351ae349d5b4e307c28b3967
diff --git a/mbtk/libmbtk_lib/net/mbtk_net_control.c b/mbtk/libmbtk_lib/net/mbtk_net_control.c
index 722efda..458f940 100755
--- a/mbtk/libmbtk_lib/net/mbtk_net_control.c
+++ b/mbtk/libmbtk_lib/net/mbtk_net_control.c
@@ -298,7 +298,7 @@
     struct timeval timeout;
     int select_r;
     int read_r;
-    struct sockaddr_nl sa;
+//    struct sockaddr_nl sa;
     struct nlmsghdr *nh;
     char buff[NET_CONTROL_BUF_SIZE];