backlight: panasonic-laptop - Fix incomplete registration failure handling
backlight: panasonic-laptop - Fix incomplete registration failure handling

Properly return backlight registration error to parent.
Mark struct backlight_ops as const.

Signed-off-by: Bruno Prémont <07d37993a092409e6c5d6be7073d31d94250624b@linux-vserver.org>
Acked-by: Harald Welte <57a0f16bf14496e20d21dd8c0873142ff0a2fbb4@gnumonks.org> (registration failure)
Signed-off-by: Richard Purdie <a03894c799ea916bd571ce8f12ed88f6fb3400f7@linux.intel.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas