[Intel-gfx] [PATCH v2] drm/i915: Clean-up idr table if context create fails.

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 6122
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                                  272/272              272/272
ILK                                  302/302              302/302
SNB                                  303/303              303/303
IVB                                  338/338              338/338
BYT                 -1              287/287              286/287
HSW                                  361/361              361/361
BDW                                  308/308              308/308
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*BYT  igt at gem_exec_bad_domains@conflicting-write-domain      PASS(14)      FAIL(1)PASS(1)
Note: You need to pay more attention to line start with '*'