app/testpmd: fix crash

Testpmd tries to calculate mbuf size based on "max Rx packet size" and
"max MTU segment number".
When driver set a "nb_mtu_seg_max" to zero, it causes division by zero
segmentation fault in testpmd.

If the PMD set "nb_mtu_seg_max" to zero, testpmd shouldn't try to
calculate the mbuf size.

Fixes: 33f9630 ("app/testpmd: create mbuf based on max supported segments")

Signed-off-by: Ferruh Yigit <[email protected]>

Author: Ferruh Yigit

app/test-pmd/testpmd.c

@@ -1174,7 +1174,8 @@ init_config(void)
 		/* Check for maximum number of segments per MTU. Accordingly
 		 * update the mbuf data size.
 		 */
-		if (port->dev_info.rx_desc_lim.nb_mtu_seg_max != UINT16_MAX) {
+		if (port->dev_info.rx_desc_lim.nb_mtu_seg_max != UINT16_MAX &&
+				port->dev_info.rx_desc_lim.nb_mtu_seg_max != 0) {
 			data_size = rx_mode.max_rx_pkt_len /
 				port->dev_info.rx_desc_lim.nb_mtu_seg_max;