On the uniprocessor kernel KiAcquirePrcbLock is a stub that doesn't modify the current Prcb's PrcbLock value.
Quickly protect this assert around CONFIG_SMP
Fixed in x86 and ARM (this was already done in x64).
This is needed because thread preparation routine KxQueueReadyThread()
releases PRCB lock, but does not acquire it, so that the locking must
always be done outside the function, same as in all its other usage cases.
This fixes an assert from release PRCB routine, when booting x86 ReactOS
in SMP mode, because it attempts to release the lock when it is not
actually acquired.
Addendum to commit a011d19ed.
+ Add an assert in KxQueueReadyThread() to ensure the PRCB lock is actually acquired.
