Xcode: Refactor internal decision for scheme generation

Move the Xcode version check out to wrap everything.

Source/cmGlobalXCodeGenerator.cxx

@@ -3279,10 +3279,11 @@ void cmGlobalXCodeGenerator::OutputXCodeProject(
 
   // Since the lowest available Xcode version for testing was 7.0,
   // I'm setting this as a limit then
-  if (root->GetMakefile()->IsOn("CMAKE_XCODE_GENERATE_SCHEME") &&
-      this->XcodeVersion >= 70) {
-    this->OutputXCodeSharedSchemes(xcodeDir);
-    this->OutputXCodeWorkspaceSettings(xcodeDir);
+  if (this->XcodeVersion >= 70) {
+    if (root->GetMakefile()->IsOn("CMAKE_XCODE_GENERATE_SCHEME")) {
+      this->OutputXCodeSharedSchemes(xcodeDir);
+      this->OutputXCodeWorkspaceSettings(xcodeDir);
+    }
   }
 
   this->ClearXCodeObjects();