pci: reject negative values in PCI id

pci: reject negative values in PCI id

The function strtoul will not return ERANGE if the input is negative, as
one might expect.

   0000:-FFFFFFFFFFFFFFFB:00.0

is not a better way to write 0000:05:00.0.
To simplify checking for '-', forbid using spaces before the field value.

   0000: 00:   2c.0

Should not be accepted.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: Gaetan Rivet <grive@u256.net>
Acked-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>