Fix T82519: Adding 2nd driver doesn't recalculate

Remove `return` from for-loop which blocked the recalculation of driven
values when it found the first driver.

Reviewed By: sybren, sergey

Differential Revision: https://developer.blender.org/D9515

source/blender/makesrna/intern/rna_fcurve.c

@@ -267,7 +267,6 @@ static void rna_DriverTarget_update_data(Main *bmain, Scene *scene, PointerRNA *
       /*BLI_findindex(&driver->targets, ptr->data) != -1)  */
       RNA_pointer_create(ptr->owner_id, &RNA_Driver, driver, &driverptr);
       rna_ChannelDriver_update_data(bmain, scene, &driverptr);
-      return;
     }
   }
 }