[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>
diff --git a/drivers/acpi/hotkey.c b/drivers/acpi/hotkey.c
index 2e2e4051..c25b2b9 100644
--- a/drivers/acpi/hotkey.c
+++ b/drivers/acpi/hotkey.c
@@ -723,6 +723,8 @@
 		goto do_fail;
 	count = tmp1 - tmp;
 	*action_handle = (char *)kmalloc(count + 1, GFP_KERNEL);
+	if (!*action_handle)
+		goto do_fail;
 	strncpy(*action_handle, tmp, count);
 	*(*action_handle + count) = 0;