Stanse found an ommitted pci_dev_puts on error path in progearbl_probe.
pmu_dev and sb_dev are gotten, but never put when
backlight_device_register fails.

So unify fail paths and put the devs when the failure occurs.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NRichard Purdie <rpurdie@linux.intel.com>