partitioning: pass along reference to parent when uninitializing.

* Fixes problems with setting the partition name after uninitializing
  a partition in DriveSetup. Previously, UninitializeJob() was
  followed by SetStringJob(), but the kernel was updating the
  change counter for the parent partition when uninitializing a
  partition, leading to SetStringJob() having an incorrect change
  counter for the parent partition. Now the parent change counter
  will be correct when SetStringJob() runs.

headers/private/kernel/disk_device_manager/KDiskDeviceUtils.h

@@ -109,13 +109,16 @@ class AutoLockerPartitionRegistration {
 public:
 	inline bool Lock(KPartition *partition)
 	{
+		if (partition == NULL)
+			return true;
 		partition->Register();
 		return true;
 	}
 
 	inline void Unlock(KPartition *partition)
 	{
-		partition->Unregister();
+		if (partition != NULL)
+			partition->Unregister();
 	}
 };
 

headers/private/kernel/disk_device_manager/ddm_userland_interface.h

@@ -77,7 +77,8 @@ status_t _user_initialize_partition(partition_id partitionID,
 				int32* changeCounter, const char* diskSystemName,
 				const char* name, const char* parameters);
 status_t _user_uninitialize_partition(partition_id partitionID,
-				int32* changeCounter);
+				int32* changeCounter, partition_id parentID,
+				int32* parentChangeCounter);
 
 status_t _user_create_child_partition(partition_id partitionID,
 				int32* changeCounter, off_t offset, off_t size,