perf completion: Strip dependency on _filedir

perf completion: Strip dependency on _filedir

_filedir is defined in the bash-completion package, but there is no need
to depend on it.  Instead, call complete with multiple -o arguments
before the -F argument like in git.git's completion script.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1372941691-14684-4-git-send-email-artagnon@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>