packagefs: Restore accidentally removed rw_lock initializations.

Incorrect rebase from the change that removes these from Node.

src/add-ons/kernel/file_systems/packagefs/nodes/Node.cpp

@@ -23,11 +23,13 @@ Node::Node(ino_t id)
 	fName(),
 	fFlags(0)
 {
+	rw_lock_init(&fLock, "packagefs node");
 }
 
 
 Node::~Node()
 {
+	rw_lock_destroy(&fLock);
 }