alpha: handle kcalloc failure

arch/alpha/kernel/module.c (module_frob_arch_sections): Handle kcalloc failure.

Signed-off-by: Jim Meyering <meyering@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>