Tycho reported that Debian uses custom LDFLAGS to
build criu, this flag get propagated into built-in
targets where we use $(LD) instead causing build
procedure to interrupt

|  LINK     arch/x86/syscalls.built-in.o
| ld: unrecognized option '-Wl,-Bsymbolic-functions'
| ld: use the --help option for usage information
| /«PKGBUILDDIR»/scripts/nmk/scripts/build.mk:141: recipe for target 'arch/x86/syscalls.built-in.o' failed

Lets make maintainers life easier and filter
out the flags we know never accepted by $(LD).
Reported-by: Tycho Andersen <tycho.andersen@canonical.com>
Tested-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>