BFS: Assert in RemovedInodes(), don't just have a comment.

This would've caught the cause of #19953.

src/add-ons/kernel/file_systems/bfs/Journal.h

@@ -28,10 +28,10 @@ public:
 			status_t		Lock(Transaction* owner,
 								bool separateSubTransactions);
 			status_t		Unlock(Transaction* owner, bool success);
+			void			AssertLocked() { ASSERT_LOCKED_RECURSIVE(&fLock); }
 
 			status_t		ReplayLog();
 
-			Transaction*	CurrentTransaction() const { return fOwner; }
 			size_t			CurrentTransactionSize() const;
 			bool			CurrentTransactionTooLarge() const;
 

src/add-ons/kernel/file_systems/bfs/Volume.cpp

@@ -414,6 +414,15 @@ Volume::WriteSuperBlock()
 }
 
 
+InodeList&
+Volume::RemovedInodes()
+{
+	// This list is guarded by the transaction lock.
+	fJournal->AssertLocked();
+	return fRemovedInodes;
+}
+
+
 void
 Volume::UpdateLiveQueries(Inode* inode, const char* attribute, int32 type,
 	const uint8* oldKey, size_t oldLength, const uint8* newKey,

src/add-ons/kernel/file_systems/bfs/Volume.h

@@ -99,8 +99,7 @@ public:
 
 			status_t		CreateVolumeID(Transaction& transaction);
 
-			InodeList&		RemovedInodes() { return fRemovedInodes; }
-				// This list is guarded by the transaction lock
+			InodeList&		RemovedInodes();
 
 			// block bitmap
 			BlockAllocator&	Allocator();