glx: Fix build in CMAKE_BUILD_TYPE=Debug
glx: Fix build in CMAKE_BUILD_TYPE=Debug

Fix this error.

glx_context.c: In function ‘glx_context_fill_attrib_list’:
glx_context.c:112:24: error: ‘dpy’ undeclared
  assert(dpy->ARB_create_context_profile);

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

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