drivers/leds/leds-lp5521.c: ret may be uninitialized

Fix it by assigning the lp5521_read return value.

Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Cc: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Arun MURTHY <arun.murthy@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>