raw/ifpga: terminate string filled by readlink with null
raw/ifpga: terminate string filled by readlink with null

readlink() does not terminate string, add a null character at the end
of the string if readlink() succeeds.

Coverity issue: 362820
Fixes: 9c006c45d0c5 ("raw/ifpga: scan PCIe BDF device tree")
Cc: stable@dpdk.org

Signed-off-by: Wei Huang <89cc104c2b51ed5072a0e69d914f07ce31ddcd43@intel.com>
Acked-by: Qi Zhang <9e9e58ffa71a29bb7b87766b362515be648fcbe0@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk