use standard list macros from queue.h and added some locking

more locking needed in marked places

Signed-off-by: Oliver Pinter <oliver.pinter@hardenedbsd.org>
wrap the lockings with macros, to easier the later changes if needed

Signed-off-by: Oliver Pinter <oliver.pinter@hardenedbsd.org>
lock entry's filed access
remove unneeded comments

Signed-off-by: Oliver Pinter <oliver.pinter@hardenedbsd.org>