platform/x86: wmi: Remove extern keyword from prototypes

The external function definitions do not need the "extern" keyword.
Remove it to silence the associated checkpatch warnings.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20251111131125.3379-4-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: Wer-Wolf

include/linux/wmi.h

@@ -36,13 +36,10 @@ struct wmi_device {
  */
 #define to_wmi_device(device)	container_of_const(device, struct wmi_device, dev)
 
-extern acpi_status wmidev_evaluate_method(struct wmi_device *wdev,
-					  u8 instance, u32 method_id,
-					  const struct acpi_buffer *in,
-					  struct acpi_buffer *out);
+acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
+				   const struct acpi_buffer *in, struct acpi_buffer *out);
 
-extern union acpi_object *wmidev_block_query(struct wmi_device *wdev,
-					     u8 instance);
+union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance);
 
 acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in);
 
@@ -81,9 +78,9 @@ struct wmi_driver {
  */
 #define to_wmi_driver(drv)	container_of_const(drv, struct wmi_driver, driver)
 
-extern int __must_check __wmi_driver_register(struct wmi_driver *driver,
-					      struct module *owner);
-extern void wmi_driver_unregister(struct wmi_driver *driver);
+int __must_check __wmi_driver_register(struct wmi_driver *driver, struct module *owner);
+
+void wmi_driver_unregister(struct wmi_driver *driver);
 
 /**
  * wmi_driver_register() - Helper macro to register a WMI driver