cgl: Fix assertion failure for unexpected context versions
cgl: Fix assertion failure for unexpected context versions

Out of habit, I accidentally put an assert(0) in a default case
statement. Instead, waffle should just emit an error and continue.

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

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