Remove a numIboIndexes=0 that is not read from GL2 tr_bsp.c

numIboIndexes is set to 0 inside the loop for each surface. Does not need to be set before loop.

code/renderergl2/tr_bsp.c

@@ -3087,7 +3087,6 @@ void R_MergeLeafSurfaces(void)
 	R_IssuePendingRenderCommands();
 
 	// actually merge surfaces
-	numIboIndexes = 0;
 	mergedSurfIndex = 0;
 	mergedSurf = s_worldData.mergedSurfaces;
 	for (i = 0; i < numWorldSurfaces; i++)