PCI: Fix typo in pci_scan_child_bus_extend()

PCI: Fix typo in pci_scan_child_bus_extend()

BugLink: https://bugs.launchpad.net/bugs/1991366
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>
(cherry picked from commit 58e011609c4305fc50674c4610cbe8a8c26261f6)
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>