fix possible null ptr deref in kallsyms_lookup

ugh, this function gets called by our unwinder. recursive backtrace for
the win... bisection to find this one was "fun."

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed