init: Remove the obsolete restorecon for /sbin files.

These files, including their building rules, have been removed in favor
of their dynamically linked versions; we no longer need to explicitly
restorecon the actual files either, for the same reason as in commit
05f96a25. When doing normal boot, these
files come from system.img, which have been labeled at build time; when
booting recovery, they don't need dedicated labels to be functional.

Test: Build and boot crosshatch.
Test: Factory reset under recovery on taimen (mke2fs).
Test: Factory reset under recovery on crosshatch (make_f2fs).
Change-Id: Icbcd24aad8be1e7f4ba7d379acd5855d256ae106