PCI: brcmstb: Fix error path after a call to regulator_bulk_get()

PCI: brcmstb: Fix error path after a call to regulator_bulk_get()

If the regulator_bulk_get() returns an error and no regulators
are created, we need to set their number to zero.

If we don't do this and the PCIe link up fails, a call to the
regulator_bulk_free() will result in a kernel panic.

While at it, print the error value, as we cannot return an error
upwards as the kernel will WARN() on an error from add_bus().

Fixes: 9e6be018b263 ("PCI: brcmstb: Enable child bus device regulators from DT")
Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20250214173944.47506-5-james.quinlan@broadcom.com
[kwilczynski: commit log, use comma in the message to match style with
other similar messages]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>