PCI: Fix typo in pci_scan_child_bus_extend()

Should be 'if' not 'of'. Fix this.

Link: https://lore.kernel.org/r/20220905080232.36087-7-mika.westerberg@linux.intel.com


Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>