[Intel-gfx] [PATCH v2] drm/i915: Simplify and fix object to display tracking

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 6104
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                 -4              272/272              268/272
ILK                                  302/302              302/302
SNB                                  303/303              303/303
IVB                                  338/338              338/338
BYT                                  287/287              287/287
HSW                                  361/361              361/361
BDW                                  308/308              308/308
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
 PNV  igt at gem_userptr_blits@coherency-sync      CRASH(2)PASS(3)      CRASH(2)
*PNV  igt at gem_fence_thrash@bo-write-verify-threaded-none      PASS(3)      CRASH(1)PASS(1)
 PNV  igt at gem_tiled_pread_pwrite      FAIL(3)PASS(2)      FAIL(2)
 PNV  igt at gen3_render_tiledx_blits      FAIL(3)PASS(1)      FAIL(2)
Note: You need to pay more attention to line start with '*'