improved code quality, few bug fixes

modules/conf_ntp.sh

@@ -38,15 +38,15 @@ conf_ntp()
 
     prnt I "Installing NTP configuration file..."
     local dest="${conf_file}.work"
-    backup_dist $conf_file
-    install_file ntp.conf $dest
-    tag_file $dest
+    backup_dist "$conf_file"
+    install_file ntp.conf "$dest"
+    tag_file "$dest"
     local line=""
     for srv in $NTP_SERVERS; do
 	line="${line}server $srv iburst\n"
     done
-    sed -i -e "s/@SERVERLIST@/$line/" $dest &&
-	mv -fv $dest $conf_file
+    sed -i -e "s/@SERVERLIST@/$line/" "$dest" &&
+	mv -fv "$dest" "$conf_file"
 
     prnt I "Starting service ntp..."