app/testpmd: fix incompatible sign for printf arguments

app/testpmd: fix incompatible sign for printf arguments

The socket_id member of struct rte_port is an unsigned int while the d
conversion specifier of printf expects an int.

The addr_bytes member of struct ether_addr is an array of uint8_t
while the X conversion specifier of printf expects an unsigned int.
Values of type uint8_t are promoted to type int when used in the
ellipsis notation of a function.

These minor bugs were found using TrustInSoft Analyzer.

Signed-off-by: Julien Cretin <julien.cretin@trust-in-soft.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>