ACPICA: fix AML mutex re-entrancy

ACPI AML supports "serialized" methods which are protected
by an implicit mutex.  The mutex is re-entrant for that AML thread
to allow recursion.

However, Linux implements notify() by creating a new AML thread.
So for systems where notify() re-enters a serialized method,
deadlock results.

The fix is to use the Linux thread_id as the key to allowing
re-entrancy, not the AML thread pointer.

http://bugzilla.kernel.org/show_bug.cgi?id=5534

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/utilities/utdelete.c

@@ -170,7 +170,6 @@ static void acpi_ut_delete_internal_obj(union acpi_operand_object *object)
 			acpi_os_delete_mutex(object->mutex.os_mutex);
 			acpi_gbl_global_lock_mutex = NULL;
 		} else {
-			acpi_ex_unlink_mutex(object);
 			acpi_os_delete_mutex(object->mutex.os_mutex);
 		}
 		break;