iplink: comment out include <net/if_packet.h>

iplink.c includes net/if_packet.h, which (on GLIBC)
only defines struct sockaddr_pkt. this struct is not
used anywhere in the code, and removing the #include
makes compilation succeed with musl libc.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

networking/libiproute/iplink.c

@@ -6,7 +6,7 @@
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 #include <net/if.h>
-#include <net/if_packet.h>
+/*#include <net/if_packet.h> - not needed? */
 #include <netpacket/packet.h>
 #include <netinet/if_ether.h>