[Intel-gfx] [PATCH v2] drm/i915: Do not leak objects after capturing error state

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 6017
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                 -2              274/274              272/274
ILK                 -1              303/303              302/303
SNB                                  303/303              303/303
IVB                 -1              342/342              341/342
BYT                                  287/287              287/287
HSW                 -1              362/362              361/362
BDW                                  308/308              308/308
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
 PNV  igt_gem_userptr_blits_minor-sync-interruptible      DMESG_WARN(1)PASS(2)      DMESG_WARN(1)PASS(1)
*PNV  igt_gen3_render_linear_blits      PASS(4)      CRASH(1)PASS(1)
*ILK  igt_gem_unfence_active_buffers      PASS(2)      DMESG_WARN(1)PASS(1)
*IVB  igt_gem_storedw_batches_loop_normal      PASS(2)      DMESG_WARN(1)PASS(1)
*HSW  igt_gem_storedw_loop_bsd      PASS(2)      DMESG_WARN(1)PASS(1)
Note: You need to pay more attention to line start with '*'