Rework support for error() on non-glibc targets:
upstream now provides its own implementation, so we can drop
the patch that adds ours; said implementation isn't
build-tested with tests, so ptest has to be disabled on musl.
This, in turns, allows dropping 0004-Fix-error-on-musl.patch.
License-Update: copyright years Signed-off-by: Alexander Kanavin <alex@linutronix.de> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
