Fix to return error code -ENOMEM from the devm_kzalloc() error handling
case instead of 0, as done elsewhere in this function.

Fixes: 6bd0dcfa ("Input: synaptics-rmi4 - factor out functions
from probe")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>