[PATCH] fault-injection: stacktrace filtering kconfig fix

`select' doesn't work very well.  With alpha `make allmodconfig' we end up
with CONFIG_STACKTRACE enabled, so we end up with undefined save_stacktrace()
at link time.

Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Don Mullis <dwm@meer.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>