[PATCH] i386: Fix up backtrace fallback patch

I didn't test all compilation combinations. Shame on me.
And fix a missing option in the boot option following x86-64 (Jan Beulich)

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>