perf tools: Catch a few uncheck calloc/malloc's

There were a few stray calloc()'s and malloc()'s which were not having
their return values checked for success.

As the calling code either already coped with failure or didn't actually
care we just return -ENOMEM at that point.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Chris Samuel <chris@csamuel.org>
LKML-Reference: <4CDDF95A.1050400@csamuel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>