drm/gem: Fix a leak in drm_gem_objects_lookup()

If the "handles" allocation or the copy_from_user() fails then we leak
"objs".  It's supposed to be freed in panfrost_job_cleanup().

Fixes: c117aa4d

 ("drm: Add a drm_gem_objects_lookup helper")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200320132334.GC95012@mwanda