perf probe: Fix to exit callback soon after finding too many probe points

Fix to exit callback soon after finding too many probe points.
Don't try to continue searching because it already failed.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20100421195632.24664.42598.stgit@localhost6.localdomain6>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>