*: remove check for errors on getsockaddr in cases we know they can't happen
libbb: make get_sock_lsa use only one getsockaddr syscall, not two

function                                             old     new   delta
get_sock_lsa                                          72     101     +29
do_iplink                                           1151    1137     -14
arping_main                                         1585    1569     -16
dolisten                                             789     755     -34
xrtnl_open                                           161      94     -67

diff --git a/networking/libiproute/iplink.c b/networking/libiproute/iplink.c
index 1e7ee07..de7d640 100644
--- a/networking/libiproute/iplink.c
+++ b/networking/libiproute/iplink.c
@@ -112,11 +112,11 @@
 	me.sll_ifindex = ifr.ifr_ifindex;
 	me.sll_protocol = htons(ETH_P_LOOP);
 	xbind(s, (struct sockaddr*)&me, sizeof(me));
-
 	alen = sizeof(me);
-	if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
-		bb_perror_msg_and_die("getsockname");
-	}
+	getsockname(s, (struct sockaddr*)&me, &alen);
+	//never happens:
+	//if (getsockname(s, (struct sockaddr*)&me, &alen) == -1)
+	//	bb_perror_msg_and_die("getsockname");
 	close(s);
 	*htype = me.sll_hatype;
 	return me.sll_halen;