perf probe: Fix to initialize fname always before use it

Fix perf probe --list to initialize fname local var always before
use it. This may cause a SEGV if there is a probe which is in
the function body but not in any inline function.

Problem introduced in:

	commit e08cfd4b
	Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
	Date:   Mon Sep 30 18:21:44 2013 +0900

	    perf probe: Fix to find line information for probe list

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131011122317.9662.29736.stgit@kbuild-fedora.novalocal


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>