power: supply: Fix null pointer dereference in smb2_probe

devm_kasprintf and devm_kzalloc return a pointer to dynamically
allocated memory which can be NULL upon failure.

Fixes: 8648aeb5 ("power: supply: add Qualcomm PMI8998 SMB2 Charger driver")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Link: https://lore.kernel.org/r/20231124075021.1335289-1-chentao@kylinos.cn


Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>