[Intel-gfx] [PATCH] drm/i915: Make WAIT_IOCTL negative timeouts be indefinite again

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 5886
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                 -2              280/280              278/280
ILK                                  308/308              308/308
SNB                 -1              328/328              327/328
IVB                                  379/379              379/379
BYT                                  294/294              294/294
HSW                                  387/387              387/387
BDW                 -1              316/316              315/316
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*PNV  igt_gen3_render_mixed_blits      FAIL(1)PASS(2)      NRUN(1)PASS(1)
*PNV  igt_gen3_render_tiledx_blits      FAIL(1)PASS(4)      CRASH(1)PASS(1)
 SNB  igt_kms_pipe_crc_basic_read-crc-pipe-A-frame-sequence      DMESG_WARN(1)PASS(4)      DMESG_WARN(1)PASS(1)
*BDW  igt_gem_gtt_hog      PASS(3)      DMESG_WARN(1)PASS(1)
Note: You need to pay more attention to line start with '*'