hw/pci-bridge: Make pxb_dev_realize_common() return if it succeeded

hw/pci-bridge: Make pxb_dev_realize_common() return if it succeeded

For the CXL PXB there is additional code after pxb_dev_realize_common()
is called.  If that realize failed (e.g. due to an out of range numa_node)
we will get a segfault.  Return a bool so the caller can check if the
pxb_dev_realize_common() succeeded or not without having to poke around
in the errp.

Fixes: 4f8db8711cbd ("hw/pxb: Allow creation of a CXL PXB (host bridge)")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20241014121902.2146424-8-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>