tests/gl_basic: Update with waffle_window_show()
tests/gl_basic: Update with waffle_window_show()

One must now call waffle_window_show() in order to display the window.

Signed-off-by: Chad Versace <a557f7f75bf28dc19ac99107f5cc7cd6b3fbdb1a@linux.intel.com>

waffle-gl/waffle,janesma/waffle,fjhenigman/waffle,chadversary/waffle,dcbaker/waffle,dcbaker/waffle,evelikov/waffle,chadversary/waffle,maurossi/waffle,fjhenigman/waffle,maurossi/waffle,yinquan529/waffle-gl-waffle,chadversary/waffle,yinquan529/waffle-gl-waffle,evelikov/waffle,dcbaker/waffle,waffle-gl/waffle,maurossi/waffle,evelikov/waffle,waffle-gl/waffle,fjhenigman/waffle,yinquan529/waffle-gl-waffle,waffle-gl/waffle,janesma/waffle,janesma/waffle