Clean up commented out code in GrDistanceFieldTextContext

SkCLZ isn't used any more. Just remove it.

BUG=skia:

Review URL: https://codereview.chromium.org/888533004

src/gpu/GrDistanceFieldTextContext.cpp

@@ -539,7 +539,6 @@ bool GrDistanceFieldTextContext::appendGlyph(GrGlyph::PackedID packed,
                               SkScalarTruncToInt(dstRect.top()),
                               SkScalarTruncToInt(dstRect.right()),
                               SkScalarTruncToInt(dstRect.bottom()))) {
-//            SkCLZ(3);    // so we can set a break-point in the debugger
         return true;
     }