i915/gem_exec_fence: KMS master is not required

Within this set of fence execution tests, we never once try to modeset;
being KMS master is not required.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

tests/i915/gem_exec_fence.c

@@ -1513,7 +1513,7 @@ igt_main
 	int i915 = -1;
 
 	igt_fixture {
-		i915 = drm_open_driver_master(DRIVER_INTEL);
+		i915 = drm_open_driver(DRIVER_INTEL);
 		igt_require_gem(i915);
 		igt_require(gem_has_exec_fence(i915));
 		gem_require_mmap_wc(i915);