Add missing error return.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34970 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/disk_device_manager/KPartition.cpp

@@ -238,6 +238,7 @@ KPartition::UnpublishDevice()
 	if (error != B_OK) {
 		dprintf("KPartition::UnpublishDevice(): Failed to get path for "
 			"partition %ld: %s\n", ID(), strerror(error));
+		return error;
 	}
 
 	error = devfs_unpublish_partition(path.Path());