Staging: vme: Correct operation of vme_lm_free

The vme_lm_free() function is not clearing up the resource created in
vme_lm_request(). In addition vme_lm_free() is void function and is used in
exit/error paths, we should wait for mutex to become free rather than
exiting and not freeing the resource.

Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>