igt/gem_ctx_thrash/threads: Allow bo resuse
igt/gem_ctx_thrash/threads: Allow bo resuse

We already allocate enough objects to thrash the ppGTT VMs, so allow us
to reuse the batch buffers for some efficiency gains and through the
contention more towards the ctx->vm.

Signed-off-by: Chris Wilson <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-wilson.co.uk>

erikarn/intel-gpu-tools,dlespiau/checkmate-test-igt,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,erikarn/intel-gpu-tools,chenxianqin/intel-gpu-tools,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,mv0/intel-gpu-tools,yipdw/intel-gpu-tools,dlespiau/checkmate-test-igt,chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,erikarn/intel-gpu-tools,mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,yipdw/intel-gpu-tools,yipdw/intel-gpu-tools,tiagovignatti/intel-gpu-tools,erikarn/intel-gpu-tools,yipdw/intel-gpu-tools,mv0/intel-gpu-tools