staging/lustre/mdc: inline llog methods

In mdc_setup() and mdc_precleanup() call mdc_llog_init() and
mdc_llog_finish() directly rather than through the OBD method wrappers
obd_llog_init() and obd_llod_finish(). Simplify the prototypes of
mdc_llog_init() and mdc_llog_finish() according to their uses.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>