Documentation: PCI: Tidy error recovery doc's PCIe nomenclature

Documentation: PCI: Tidy error recovery doc's PCIe nomenclature

Commit 11502feab423 ("Documentation: PCI: Tidy AER documentation")
replaced the terms "PCI-E", "PCI-Express" and "PCI Express" with "PCIe"
in the AER documentation.

Do the same in the documentation on PCI error recovery.  While at it,
add a missing period and a missing blank.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/db56b7ef12043f709a04ce67c1d1e102ab5f4e19.1757942121.git.lukas@wunner.de