leds/leds-regulator.c: fix handling of already enabled regulators

Make the driver aware of the initial status of the regulator.

The leds-regulator driver was ignoring the initial status of the
regulator; this resulted in rdev->use_count being incremented to 2 after
calling regulator_led_set_value() in the .probe method when a regulator
was already enabled at insmod time, which made it impossible to ever
disable the regulator.

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Antonio Ospite <ospite@studenti.unina.it>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>