Fix for [#35490] Initial cube is green, turn off matcap and it is correct color
* Own error from r56980, "smooth" is an Interpolation qualifier in GLSL, so use another variable name to avoid the error. 

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@57003 954f8c5b-7b00-dc11-b283-0030488c597c