ACPI / battery: drop inclusion of init.h

The driver can be built as a module thus inclusion of init.h is
redundant in battery.c since it's always included by module.h.
Suggested-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NDmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/battery.c

@@ -27,7 +27,6 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
-#include <linux/init.h>
 #include <linux/types.h>
 #include <linux/jiffies.h>
 #include <linux/async.h>