gl_basic: Clean up usage errors
gl_basic: Clean up usage errors

Add new function usage_error_printf() to simply emission of usage
errors.

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

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