Fix extra comma typo (#18262)

Marlin/src/module/configuration_store.cpp

       #if EXTRUDERS == 1
         CONFIG_ECHO_START();
         SERIAL_ECHOLNPAIR("  M200 S", int(parser.volumetric_enabled)
-                              , " D", LINEAR_UNIT(planner.filament_size[0]),
+                              , " D", LINEAR_UNIT(planner.filament_size[0])
                               #if ENABLED(VOLUMETRIC_EXTRUDER_LIMIT)
                                 , " L", LINEAR_UNIT(planner.volumetric_extruder_limit[0])
                               #endif