dmi: Let dmi_walk() users pass private data

At the moment, dmi_walk() lacks flexibility, users can't pass data to
the callback function. Add a pointer for private data to make this
function more flexible.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index 16e11c2..af9f430 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -103,7 +103,7 @@
 	da_num_tokens += tokens;
 }
 
-static void find_tokens(const struct dmi_header *dm)
+static void find_tokens(const struct dmi_header *dm, void *dummy)
 {
 	switch (dm->type) {
 	case 0xd4: /* Indexed IO */
@@ -356,7 +356,7 @@
 	if (!dmi_check_system(dell_device_table))
 		return -ENODEV;
 
-	dmi_walk(find_tokens);
+	dmi_walk(find_tokens, NULL);
 
 	if (!da_tokens)  {
 		printk(KERN_INFO "dell-laptop: Unable to find dmi tokens\n");