lspci: Fix detection of memory space bar

lspci: Fix detection of memory space bar

intel-conf1 backend never show AtomicOpsCap: capabilities despite the fact
that is successfuly detects memory bars on device. But other backends show
this capability.

Error is in device_has_memory_space_bar() function, it expects that ->size
member is always filled. But size of the BAR is not available in PCI config
space and therefore raw backends cannot retrieve it.

Probably intention of the non-zero check was to verify that base address
was filled with non-zero size. So either base address is non-zero or length
is non-zero. Adjust check.