ACPI: button: fix some coding style issues

Fix some coding style issues reported by checkpatch.pl, including the
following types:

WARNING: Block comments use * on subsequent lines
WARNING: Block comments use a trailing */ on a separate line
ERROR: code indent should use tabs where possible
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/button.c

@@ -156,10 +156,7 @@ static unsigned long lid_report_interval __read_mostly = 500;
 module_param(lid_report_interval, ulong, 0644);
 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
 
-/* --------------------------------------------------------------------------
-                              FS Interface (/proc)
-   -------------------------------------------------------------------------- */
-
+/* FS Interface (/proc) */
 static struct proc_dir_entry *acpi_button_dir;
 static struct proc_dir_entry *acpi_lid_dir;
 
@@ -348,9 +345,7 @@ static int acpi_button_remove_fs(struct acpi_device *device)
 	return 0;
 }
 
-/* --------------------------------------------------------------------------
-                                Driver Interface
-   -------------------------------------------------------------------------- */
+/* Driver Interface */
 int acpi_lid_open(void)
 {
 	if (!lid_device)