init: Fix memory corruption when sanitizing platform paths

This commit fixes code that incorrectly increments s when it
hits the terminator character of the string being sanitized.
This means it will randomly start trashing memory beyond the
end of the string being sanitized until it happens to hit two
NULs (\0\0) which will break it out of the loop.

(cherry picked from commit 07f3fee1)

Bug: 18885357
Change-Id: If6b01fe2b9bd5985f08f1278deb03b311d0170dc