starmath: Drop redundant SetLineColor() call

10 lines later the same code appears again.

Change-Id: I06bccbb89e9bc3dd1339ca4f8c2482a2ee75c9f2
Reviewed-on: https://gerrit.libreoffice.org/27176Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Takeshi Abe <tabe@fixedpoint.jp>

starmath/source/visitors.cxx

@@ -218,8 +218,6 @@ void SmCaretDrawingVisitor::Visit( SmTextNode* pNode )
 
 void SmCaretDrawingVisitor::DefaultVisit( SmNode* pNode )
 {
-    mrDev.SetLineColor( Color( COL_BLACK ) );
-
     //Find the line
     SmNode* pLine = SmCursor::FindTopMostNodeInLine( pNode );