use MSG_TRUNC flag to get recv message size at once
use MSG_TRUNC flag to get recv message size at once

prevent multiple calls of recvmsg.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
(cherry picked from commit d733f8a0a65a817d16ebaa1a8f5ad1330682b489)

Conflicts:
	lib/nl.c

Signed-off-by: Thomas Graf <17c2d8920621522552b392f72d8fdb4d1e866b44@suug.ch>

tgraf/libnl-1.1-stable,tgraf/libnl-1.1-stable,Distrotech/libnl-1,Distrotech/libnl-1