lib/route: Fix appending IFLA_BRPORT_FASTLEAVE
lib/route: Fix appending IFLA_BRPORT_FASTLEAVE

This patch fixes IFLA_BRPORT_FASTLEAVE to append to the correct
netlink attribute. (Turned up in automated testing.)

Fixes: 55bc931a7272e6ac8f555bcc2a373eb2b6b58377

Signed-off-by: Jef Oliver <058c60142e43738450522c7fe962fe2863b1f3d2@intel.com>
Signed-off-by: Thomas Haller <16e26612e4159990a6b3691e92592e691ff74132@redhat.com>

dsahern/libnl,tklauser/libnl,HolyShitMan/libnl-1,tklauser/libnl,thom311/libnl,greearb/libnl-ct,greearb/libnl-ct,HolyShitMan/libnl-1,HolyShitMan/libnl-1,greearb/libnl-ct,dsahern/libnl,HolyShitMan/libnl-1,thom311/libnl,dsahern/libnl,tklauser/libnl,thom311/libnl,dsahern/libnl,tklauser/libnl