PCI: Don't fallback to bus reset after failed slot reset

PCI: Don't fallback to bus reset after failed slot reset

If a bus has hotplug slots that implement the slot's reset_slot callback,
it is not safe to do the non-slot specific bus reset, so don't fallback to
it. If a slot reset does fail, the subsequent bus reset will attempt a 2nd
link reset on top of previous and fail to handle the hotplug events.

Fixes: 8238cb69c01fe ("PCI: Make reset_subordinate hotplug safe")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260421150644.3543733-1-kbusch@meta.com