Remove the initialization of pci_ignore_seg to false which is pointless.

Link: https://lore.kernel.org/r/20211203080758.962-1-guolongji@uniontech.comSigned-off-by: Longji Guo <guolongji@uniontech.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>