dcd_da146xx: Clear transfer data on dcd_edpt_close

Closing endpoint clears data in affected xfer_ctl_t

src/portable/dialog/da146xx/dcd_da146xx.c

@@ -939,6 +939,7 @@ void dcd_edpt_close(uint8_t rhport, uint8_t ep_addr)
       }
     }
   }
+  tu_memclr(xfer, sizeof(*xfer));
 }
 
 bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t total_bytes)