[Intel-gfx] [PATCH] drm/i915/bdw: Clean up execlist queue items in

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
-------------------------------------Summary-------------------------------------
Platform: baseline_drm_intel_nightly_pass_rate->patch_applied_pass_rate
BYT: pass/total=1/1->1/1
PNV: pass/total=1/1->1/1
ILK: pass/total=1/1->1/1
IVB: pass/total=1/1->1/1
SNB: pass/total=1/1->1/1
HSW: pass/total=1/1->1/1
BDW: pass/total=1/1->1/1
-------------------------------------Detailed-------------------------------------
test_platform: test_suite, test_case, result_with_drm_intel_nightly->result_with_patch_applied