perf tests: Fix compile errors in bp_signal files

perf tests: Fix compile errors in bp_signal files

When building on powerpc,  we get compile errors in bp_signal.c and
bp_signal_overflow.c due to __u64 and '%llx'.

Powerpc, needs __SANE_USERSPACE_TYPES__ to be defined so we pick up
<asm-generic/int-ll64.h> and define __u64 as unsigned long long.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20130426173320.GA7029@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>