video_VideoSeek: correct nyan board name expression

Correct board name expression from "nyan-*" to "nyan_*"

BUG=chromium:723982
TEST=manual test

Change-Id: If6cc36c8f2c643a04408641af1ad9cd47e5dd870
Reviewed-on: https://chromium-review.googlesource.com/513842
Commit-Ready: Pin-chih Lin <johnylin@chromium.org>
Tested-by: Pin-chih Lin <johnylin@chromium.org>
Reviewed-by: Kuang-che Wu <kcwu@chromium.org>
diff --git a/client/site_tests/video_VideoSeek/video_VideoSeek.py b/client/site_tests/video_VideoSeek/video_VideoSeek.py
index 62a153c..1344c2a 100755
--- a/client/site_tests/video_VideoSeek/video_VideoSeek.py
+++ b/client/site_tests/video_VideoSeek/video_VideoSeek.py
@@ -29,7 +29,7 @@
 
                 # Disable vp8 switchres for nyan devices temporarily due to:
                 # crbug/699260
-                ('nyan', 'vp8', True), ('nyan-*', 'vp8', True)
+                ('nyan', 'vp8', True), ('nyan_*', 'vp8', True)
         ]
 
         board = utils.get_current_board()