[Intel-gfx] [PATCH 2/2] drm/i915: Move drm_framebuffer_unreference out of struct_mutex for takeover

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 5783
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                 -1              277/277              276/277
ILK                                  313/313              313/313
SNB                 -1              309/309              308/309
IVB                                  382/382              382/382
BYT                                  296/296              296/296
HSW                                  425/425              425/425
BDW                 -1              318/318              317/318
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*PNV  igt_drm_vma_limiter_cached      NRUN(1)PASS(1)      NO_RESULT(1)PASS(1)
*SNB  igt_kms_plane_plane-position-covered-pipe-B-plane-1      PASS(2)      DMESG_WARN(1)PASS(1)
*BDW  igt_gem_gtt_hog      PASS(5)      DMESG_WARN(1)PASS(1)
Note: You need to pay more attention to line start with '*'