v3d: Fix check for TFU job completion in the simulator.

v3d: Fix check for TFU job completion in the simulator.

We're waiting for the jobs-completed count to increment (with wrapping),
not to reach its starting state.  This mostly ended up working out because
the next v3d_hw_tick() for a submit CL would end up doing the TFU
operation first, but it did fail when a blit was used for glReadPixels()
at the end of a test.

Fixes: ee0549ff9ab3 ("v3d: Add the V3D TFU submit interface to the simulator.")