misc: bh1770glc: Use managed functions

This patch introduces the use of managed interfaces like devm_kzalloc,
devm_regulator_bulk_get and does away with the functions to free the
allocated memory in the probe and remove functions. Also, some labels
are removed and renamed to preserve the ordering.

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>