Acquire CCheckQueue's lock to avoid race condition
Acquire CCheckQueue's lock to avoid race condition

This fixes a potential race condition in the CCheckQueueControl constructor,
which was looking directly at data in CCheckQueue without acquiring its lock.

Remove the now-unnecessary friendship for CCheckQueueControl

Rebased-From: cf008ac8c3c5d582562d88ad89020daef3e64dcb
Github-Pull: #5721

domob1812/crowncoin,domob1812/crowncoin,Crowndev/crowncoin,Infernoman/crowncoin,Crowndev/crowncoin,domob1812/crowncoin,Crowndev/crowncoin,Crowndev/crowncoin,Crowndev/crowncoin,domob1812/crowncoin,domob1812/crowncoin,domob1812/crowncoin,Infernoman/crowncoin,Infernoman/crowncoin,Crowndev/crowncoin,Infernoman/crowncoin,Infernoman/crowncoin,Infernoman/crowncoin