[hostinfo] Use os-release only if non-empty

src/modules/hostinfo/HostInfoJob.cpp

@@ -67,10 +67,12 @@ hostOSName()
 {
 #ifdef WITH_KOSRelease
     KOSRelease r;
+    if ( !r.name().isEmpty() )
+    {
         return r.name();
-#else
+    }
-    return hostOS();
 #endif
+    return hostOS();
 }
 
 static QString