peerprofile: Check the result of `open()`

Change-Id: Ib5af845fbdc039a8986c680ad650ce04aed66bcc
Reviewed-by: Nicolas Jäger <nicolas.jager@savoirfairelinux.com>

src/peerprofilecollection.cpp

@@ -74,7 +74,12 @@ bool PeerProfileEditor::save(const Person* pers)
     const auto& result = pers->toVCard();
 
     QFile file {filename};
-    file.open(QIODevice::WriteOnly);
+
+    if (Q_UNLIKELY(!file.open(QIODevice::WriteOnly))) {
+        qWarning() << "Can't write to" << filename;
+        return false;
+    }
+
     file.write(result);
     file.close();
     return true;