pci: fix build on FreeBSD

pci: fix build on FreeBSD

Build log:
lib/librte_eal/bsdapp/eal/eal_pci.c:462:9: error:
incompatible integer to pointer conversion passing 'u_int32_t'
(aka 'unsigned int') to parameter of type 'void *'

It is fixed by passing the pointer of pi.pi_data to memcpy.

By the way, it seems strange that pi_data is initialized twice:
	.pi_data = *(u_int32_t *)buf
	memcpy(&pi.pi_data, buf, len);

Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>