Revert "FORTIFY_SOURCE: fortify strrchr"

This reverts commit f9c4e0a57ce9b5a96a7bccdb690bf8ae4084af65.

Revert "FORTIFY_SOURCE: fortify strchr"

This reverts commit 837ff616a8b7458f2d66bffcfec5b43c5f9226d4.

Conflicts:
	libc/include/string.h