If g_pInterface is set to NULL outside the critical section in one thread
while another thread is in the critical section, the channel client context
allocated in the VirtualChannelEntry won't end up getting freed.
The channel client context is normally loaded from g_pInterface in
FreeRDP_VirtualChannelInit and stored in the pChannelInitData, then copied
from there onto the pChannelOpenData structure in FreeRDP_VirtualChannelOpen
and finally freed in freerdp_channels_free.
99228ee254