FilePath: Fix for operator+(QString)

Change-Id: I3b9889c8b2cdc8a9d1bf94c3e7a8627e2ff2ac35
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/filepath.cpp

@@ -977,9 +977,7 @@ bool FilePath::operator>=(const FilePath &other) const
 
 FilePath FilePath::operator+(const QString &s) const
 {
-    FilePath res = *this;
-    res.m_path += s;
-    return res;
+    return pathAppended(s);
 }
 
 /// \returns whether FilePath is a child of \a s