ebtables: fix miscompilation on 64bit targets

ebtables: fix miscompilation on 64bit targets

The musl build "fix" introduced in r45108 removed all netinet/ether.h
includes, which made the prototypes of ether_aton and ether_ntoa
unavailable. As a result, the compiler assumed they return int instead
of a pointer. This currupted the pointer on 64bit targets, causing ebtables
to segfault in commands containing MAC addresses.

Since r46161 made it possible to include both the kernel and the libc
if_ether.h as long as the libc version is included first, this patch
changes the fix to remove the linux/if_ether.h from the ebtables source
(so the fixed version from the kernel is used) and ensures netinet/ether.h
is included early.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@46292 3c298f89-4303-0410-b956-a3cf2f4a3e73