tests/kms_*: Use correct DRM context version

DRM_EVENT_CONTEXT_VERSION is the latest context version supported by
whatever version of libdrm is present. igt was blindly asserting it
supported whatever version that may be, even if it actually didn't.

With libdrm 2.4.78, setting a higher context version than 2 will attempt
to call the page_flip_handler2 vfunc if it was non-NULL, which being a
random chunk of stack memory, it might well have been.

Set the version as 2, which should be bumped only with the appropriate
version checks.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Petri Latvala <petri.latvala@intel.com>
diff --git a/tests/kms_rotation_crc.c b/tests/kms_rotation_crc.c
index 4347884..8306cf2 100644
--- a/tests/kms_rotation_crc.c
+++ b/tests/kms_rotation_crc.c
@@ -233,7 +233,7 @@
 
 static void wait_for_pageflip(int fd)
 {
-	drmEventContext evctx = { .version = DRM_EVENT_CONTEXT_VERSION };
+	drmEventContext evctx = { .version = 2 };
 	struct timeval timeout = { .tv_sec = 0, .tv_usec = 50000 };
 	fd_set fds;
 	int ret;