[Intel-gfx] [PATCH] drm/i915: use the correct obj when preparing

[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=277/348->277/348
PNV: pass/total=323/328->325/328
ILK: pass/total=328/330->330/330
IVB: pass/total=545/546->544/546
SNB: pass/total=558/563->562/563
HSW: pass/total=587/591->590/591
BDW: pass/total=435/435->434/435
-------------------------------------Detailed-------------------------------------
test_platform: test_suite, test_case, result_with_drm_intel_nightly(count, machine_id...)...->result_with_patch_applied(count, machine_id)...
PNV: Intel_gpu_tools, igt_gem_mmap_offset_exhaustion, DMESG_WARN(2, M23M24)PASS(14, M24M23M7) -> PASS(4, M7)
PNV: Intel_gpu_tools, igt_gem_unref_active_buffers, DMESG_WARN(2, M23)PASS(14, M24M23M7) -> PASS(4, M7)
ILK: Intel_gpu_tools, igt_kms_render_gpu-blit, DMESG_WARN(1, M26)PASS(15, M6M26M37) -> PASS(4, M6)
ILK: Intel_gpu_tools, igt_kms_flip_wf_vblank-vs-dpms-interruptible, DMESG_WARN(1, M26)PASS(15, M6M26M37) -> PASS(4, M6)
IVB: Intel_gpu_tools, igt_gem_bad_reloc_negative-reloc, NSPT(5, M4M34)PASS(11, M34M4) -> NSPT(2, M4)PASS(2, M4)
IVB: Intel_gpu_tools, igt_kms_plane_plane-position-covered-pipe-A-plane-1, TIMEOUT(1, M34)PASS(9, M4) -> PASS(4, M4)
IVB: Intel_gpu_tools, igt_kms_flip_absolute-wf_vblank-interruptible, PASS(4, M34M4) -> DMESG_WARN(1, M4)PASS(3, M4)
SNB: Intel_gpu_tools, igt_kms_cursor_crc_cursor-256x256-sliding, DMESG_WARN(3, M35M22)PASS(7, M22M35) -> PASS(4, M35)
SNB: Intel_gpu_tools, igt_kms_plane_plane-panning-top-left-pipe-A-plane-1, PASS(1, M35) -> FAIL(1, M35)PASS(3, M35)
SNB: Intel_gpu_tools, igt_pm_rpm_legacy-planes, TIMEOUT(1, M35) -> TIMEOUT(3, M35)PASS(1, M35)
SNB: Intel_gpu_tools, igt_pm_rpm_legacy-planes-dpms, TIMEOUT(1, M35) -> TIMEOUT(3, M35)PASS(1, M35)
SNB: Intel_gpu_tools, igt_pm_rpm_universal-planes, TIMEOUT(1, M35) -> TIMEOUT(2, M35)PASS(1, M35)
SNB: Intel_gpu_tools, igt_pm_rpm_universal-planes-dpms, TIMEOUT(1, M35) -> PASS(1, M35)
HSW: Intel_gpu_tools, igt_gem_bad_reloc_negative-reloc, NSPT(4, M39M20M40)PASS(9, M40M39M20) -> NSPT(2, M19)PASS(2, M19)
HSW: Intel_gpu_tools, igt_pm_rpm_legacy-planes, TIMEOUT(1, M40) -> TIMEOUT(3, M19)PASS(1, M19)
HSW: Intel_gpu_tools, igt_pm_rpm_legacy-planes-dpms, TIMEOUT(1, M40) -> TIMEOUT(3, M19)PASS(1, M19)
HSW: Intel_gpu_tools, igt_pm_rpm_universal-planes, TIMEOUT(1, M40) -> TIMEOUT(2, M19)PASS(1, M19)
HSW: Intel_gpu_tools, igt_pm_rpm_universal-planes-dpms, TIMEOUT(1, M40) -> PASS(1, M19)
BDW: Intel_gpu_tools, igt_gem_reset_stats_ban-bsd, PASS(16, M30M28M42) -> DMESG_WARN(1, M30)PASS(3, M30)