doc: fix KNI PMD name typo

[ upstream commit 08c724b ]

The KNI PMD name should be "net_kni".

Fixes: 75e2bc5 ("net/kni: add KNI PMD")

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>

doc/guides/nics/kni.rst

@@ -33,7 +33,7 @@ Usage
 
 EAL ``--vdev`` argument can be used to create KNI device instance, like::
 
-        dpdk-testpmd --vdev=net_kni0 --vdev=net_kn1 -- -i
+        dpdk-testpmd --vdev=net_kni0 --vdev=net_kni1 -- -i
 
 Above command will create ``kni0`` and ``kni1`` Linux network interfaces,
 those interfaces can be controlled by standard Linux tools.