[HAL][ETH] Fix the calculation of the tail pointer so that it points to the last updated descriptor

    edit 5263450 [HAL][ETH] Fix the calculation of the tail pointer so that it points to the last updated descriptor

Src/stm32h7xx_hal_eth.c

diff --git a/Src/stm32h7xx_hal_eth.c b/Src/stm32h7xx_hal_eth.c
index 2536a73..77cbabe 100644
--- a/Src/stm32h7xx_hal_eth.c
+++ b/Src/stm32h7xx_hal_eth.c
@@ -1209,7 +1209,7 @@
   if (heth->RxDescList.RxBuildDescCnt != desccount)
   {
     /* Set the tail pointer index */
-    tailidx = (descidx + 1U) % ETH_RX_DESC_CNT;
+    tailidx = (ETH_RX_DESC_CNT + descidx - 1U) % ETH_RX_DESC_CNT;
 
     /* DMB instruction to avoid race condition */
     __DMB();