If "regl_pdata->n_regulators == 0" is true then we accidentally return
PTR_ERR(<some_valid_pointer>) instead of an error code.  I've changed it
to return -ENODEV instead.

Fixes: 69ca3e58 ("regulator: da9063: Add Dialog DA9063 voltage regulators support.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>