Critical Sections using TLR_LCK_ENTER/TLR_LCK_LEAVE do not work as expected.

While restructuring the profinet stack to use TLR_LCK_* functions for critical areas it turned out, that calls to certain functions may unintentionally release an aquired lock. This happens because some functions internally use mutex/semaphores which in turn result in calls to the scheduler and reenabling interrupts.

The following functions (incomplete) are affected and should never be used inside of such a lock:

• LIB_MALLOC
• LIB_FREE