Call roundf() instead of _hb_roundf()

The former is defined as a macro expanding to the latter.

src/OT/Color/COLR/COLR.hh

@@ -1514,10 +1514,10 @@ struct ClipBoxFormat2 : Variable<ClipBoxFormat1>
     value.get_clip_box(clip_box, instancer);
     if (instancer)
     {
-      clip_box.xMin += _hb_roundf (instancer (varIdxBase, 0));
-      clip_box.yMin += _hb_roundf (instancer (varIdxBase, 1));
-      clip_box.xMax += _hb_roundf (instancer (varIdxBase, 2));
-      clip_box.yMax += _hb_roundf (instancer (varIdxBase, 3));
+      clip_box.xMin += roundf (instancer (varIdxBase, 0));
+      clip_box.yMin += roundf (instancer (varIdxBase, 1));
+      clip_box.xMax += roundf (instancer (varIdxBase, 2));
+      clip_box.yMax += roundf (instancer (varIdxBase, 3));
     }
   }
 };

src/OT/Layout/GPOS/GPOS.hh

@@ -156,7 +156,7 @@ GPOS::position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
   {
     for (unsigned i = 0; i < len; i++)
       if (unlikely (pos[i].y_offset))
-        pos[i].x_offset += _hb_roundf (font->slant_xy * pos[i].y_offset);
+        pos[i].x_offset += roundf (font->slant_xy * pos[i].y_offset);
   }
 }
 

src/hb-ot-metrics.cc

@@ -196,7 +196,7 @@ hb_ot_metrics_get_position (hb_font_t           *font,
 	*position *= mult;
 
 	if (font->slant)
-	  *position += _hb_roundf (mult * font->slant_xy * rise);
+	  *position += roundf (mult * font->slant_xy * rise);
       }
 
       return ret;