busybox: sync do_install() with oe master (mostly)
This is basically a backport of the current state of the art from the
openembedded master repo. In particular this fixes an installation
error on micro:
| + cp -dPr /home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image/bin /home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image/sbin /home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image /home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image/busybox/
| cp: will not create hard link `/home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image/busybox/image/bin' to directory `/home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image/busybox/bin'
| cp: cannot copy a directory, `/home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image', into itself, `/home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/image/busybox/image'
| ERROR: Function 'do_install' failed (see /home/pb/oe/build-meta/tmp-eglibc/work/i586-oe-linux/busybox-1.18.4-r1.2/temp/log.do_install.3808 for further information)
