Fix screenshot test due main axis justification refactor

Reviewed By: emilsjolander

Differential Revision: D6923178

fbshipit-source-id: d8f81b06d9127c75daecffb73b5e6c5abbad8ade

ReactCommon/yoga/yoga/Yoga.cpp

@@ -2062,7 +2062,7 @@ static void YGJustifyMainAxis(
        i < collectedFlexItemsValues.endOfLineIndex;
        i++) {
     const YGNodeRef child = node->getChild(i);
-    if (style.positionType == YGPositionTypeRelative) {
+    if (child->getStyle().positionType == YGPositionTypeRelative) {
       if (child->marginLeadingValue(mainAxis).unit == YGUnitAuto) {
         numberOfAutoMarginsOnCurrentLine++;
       }