[ACPI] drivers/acpi/hotkey.c: check kmalloc return value

Signed-off-by: Irwan Djajadi <irwan.djajadi@iname.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
1 file changed