PCI: endpoint: Remove goto labels in pci_epf_create()

Remove the pci_epf_create() goto labels completely and handle the
errors at the respective call site to simplify the function error
handling.

Signed-off-by: Rolf Evers-Fischer <rolf.evers.fischer@aptiv.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>