fu740_pcie_host_init() assigned "ret", but never used the value.  Drop it.

Found by Krzysztof using cppcheck:

  $ cppcheck --enable=all --force
  unreadVariable drivers/pci/controller/dwc/pcie-fu740.c:227 Variable 'ret' is assigned a value that is never used.
Reported-by: NKrzysztof Wilczyński <kw@linux.com>
Link: https://lore.kernel.org/r/20220313192933.434746-4-helgaas@kernel.orgSigned-off-by: NBjorn Helgaas <bhelgaas@google.com>