PCI: Use max() instead of max_t() to ease static analysis

PCI: Use max() instead of max_t() to ease static analysis

In this code:

  used_buses = max_t(unsigned int, available_buses,
                     pci_hotplug_bus_size - 1);

max_t() casts the 'unsigned long' pci_hotplug_bus_size (either 32 or 64
bits) to 'unsigned int' (32 bits) result type, so there's a potential of
discarding significant bits.

Instead, use max(a, b), which casts 'unsigned int' to 'unsigned long' and
cannot discard significant bits.

In this case, pci_hotplug_bus_size is constrained to <= 0xff by pci_setup()
so this doesn't fix a bug, but it makes static analysis easier.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20251119224140.8616-26-david.laight.linux@gmail.com