[Intel-gfx] [PATCH] drm: Add integer overflow checking to transitional plane helpers

[shuang.he at intel.com]

Tested-By: Intel Graphics QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 6130
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                 -2              272/272              270/272
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
 PNV  igt at gem_tiled_pread_pwrite      FAIL(3)PASS(11)      FAIL(1)PASS(1)
 PNV  igt at gem_userptr_blits@coherency-sync      CRASH(5)PASS(8)      CRASH(1)PASS(1)
*BYT  igt at gem_exec_bad_domains@conflicting-write-domain      PASS(18)      FAIL(1)PASS(1)
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