perf tools: Use kmod_path__parse in map_groups__set_modules_path_dir

Replacing the file name parsing with kmod_path__parse
and moving the dso update into new separate function.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-q0ed76ajcyoaofotntrg5sla@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>