leds: lm3556: don't call kfree for the memory allocated by devm_kzalloc

leds: lm3556: don't call kfree for the memory allocated by devm_kzalloc

The devm_* functions eliminate the need for manual resource releasing
and simplify error handling. Resources allocated by devm_* are freed
automatically on driver detach.

Thus adding kfree calls here will introduce double free bug.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Geon Si Jeong <gshark.jeong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>