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: 33f9630fc23d ("app/testpmd: create mbuf based on max supported segments")
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
163fbaafa2