fs/ntfs3: Fix a resource leak bug in wnd_extend()

Add put_bh() to decrease the refcount of 'bh' after the job
is finished, preventing a resource leak.

Fixes: 3f3b442b5ad2 ("fs/ntfs3: Add bitmap")
Cc: [e-mail]
Signed-off-by: Haoxiang Li <[e-mail]>
Signed-off-by: Konstantin Komarov <[e-mail]>

fs/ntfs3/bitmap.c

···
 		mark_buffer_dirty(bh);
 		unlock_buffer(bh);
 		/* err = sync_dirty_buffer(bh); */
+		put_bh(bh);
 
 		b0 = 0;
 		bits -= op;