Include zdb in initramfs

zdb is useful for debugging during early boot.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Add exit 1 to waitForZFS

Proper use of call_func_timeout() requires that we return an exit status
of 1 upon success.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Detect grub2-mkconfig failure

Signed-off-by: Richard Yao <ryao@gentoo.org>
Copy ld.so.conf and friends when copy_binaries is used

This fixes "error while loading shared libraries libgcc_s.so.1 cannot
open shared object file" when attempting to import a root pool on ARM.

Signed-off-by: Richard Yao <ryao@gentoo.org>