PCI: Prefer 'unsigned int' over bare 'unsigned'

The bare "unsigned" type implicitly means "unsigned int", but the preferred
coding style is to use the complete type name.

Update the bare use of "unsigned" to the preferred "unsigned int".

No change to functionality intended.

See a1ce18e4 ("checkpatch: warn on bare unsigned or signed declarations
without int").

Link: https://lore.kernel.org/r/20211013014136.1117543-1-kw@linux.com


Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>