[App] code style fixes by MSVC

- automatic .clang fixes while checking for nullptr, no actual code change

src/App/PropertyLinks.cpp

@@ -115,7 +115,7 @@ void PropertyLinkBase::unregisterLabelReferences()
 
 void PropertyLinkBase::getLabelReferences(std::vector<std::string> &subs,const char *subname) {
     const char *dot;
-    for(;(subname=strchr(subname,'$'))!=nullptr; subname=dot+1) {
+    for (; (subname = strchr(subname, '$')) != nullptr; subname = dot + 1) {
         ++subname;
         dot = strchr(subname,'.');
         if(!dot) break;
@@ -154,7 +154,7 @@ std::string PropertyLinkBase::updateLabelReference(const App::DocumentObject *pa
     // hierarchies, we have to search for all occurrences, and make sure the
     // referenced sub-object at the found hierarchy is actually the given
     // object.
-    for(const char *pos=subname; ((pos=strstr(pos,ref.c_str()))!=nullptr); pos+=ref.size()) {
+    for (const char *pos = subname; ((pos = strstr(pos, ref.c_str())) != nullptr); pos += ref.size()) {
         auto sub = std::string(subname,pos+ref.size()-subname);
         auto sobj = parent->getSubObject(sub.c_str());
         if(sobj == obj) {