app/testpmd: fix displaying RSS hash functions

app/testpmd: fix displaying RSS hash functions

Command shouldn't ask RSS hash functions as argument to get supported
RSS hash function, those values will be overwritten by PMD anyway.

To display configured RSS hash functions
"show port (port_id) rss-hash"

To display configured RSS hash functions and hash key
"show port (port_id) rss-hash key"

Fixes: 8205e241b2b0 ("app/testpmd: add missing type to RSS hash commands")
Cc: stable@dpdk.org
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Bernard Iremonger <bernard.iremonger@intel.com>