Commit d77ffb68 added not only reporting of the PCI header type, but
also parsing of that information.  However, because there was no parsing
done for the other sub-PCI capabilities, if there was any other
capability then a valid header type name (like phys_function or
virt_functions) the parsing would fail.  This prevented passing node
device XMLs that we generated into our own functions when dealing with,
e.g. with SRIOV cards.

Instead of reworking the whole parsing, just fix this one occurence and
remove a test for it for the time being.  Future patches will deal with
the rest.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>