perf annotate: Fix -i option, which is currently ignored.

Assign input_name, received from program arguments, to file data
structure.

Signed-off-by: Martin Liska <mliska@suse.cz>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/55685654.2010209@suse.cz


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