wflinfo: find glGetStringi on both Mali and WGL
wflinfo: find glGetStringi on both Mali and WGL

Do the glGetStringi lookup after making context current so it works on WGL.
Remove an incorrect glGetStringi lookup, which returned NULL on Mali.

Signed-off-by: Frank Henigman <4f3ccfa167f952ff7263448ff4377acff6a23e5c@google.com>
Reviewed-by: Chad Versace <a557f7f75bf28dc19ac99107f5cc7cd6b3fbdb1a@intel.com>

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