conf: Fix error flow in virDomainPCIAddressEnsureAddr()
conf: Fix error flow in virDomainPCIAddressEnsureAddr()

This avoids setting 'ret' multiple times, which will result
in errors being masked if the first operation fails but the
second one succeeds.

Introduced-by: f183b87fc1dbcc6446ac3c1cef9cdd345b9725fb
Spotted-by: Coverity
Reported-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>
Signed-off-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>
Reviewed-by: Pavel Hrdina <d4772d05997b8abf035041e3b4f4996380ea7e7a@redhat.com>

fabianfreyer/libvirt,libvirt/libvirt,andreabolognani/libvirt,olafhering/libvirt,jardasgit/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jfehlig/libvirt,nertpinx/libvirt,eskultety/libvirt,fabianfreyer/libvirt,eskultety/libvirt,jfehlig/libvirt,andreabolognani/libvirt,crobinso/libvirt,crobinso/libvirt,jardasgit/libvirt,zippy2/libvirt,andreabolognani/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,zippy2/libvirt,crobinso/libvirt,jfehlig/libvirt,zippy2/libvirt,nertpinx/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,libvirt/libvirt,eskultety/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt,eskultety/libvirt,andreabolognani/libvirt,jardasgit/libvirt,libvirt/libvirt,olafhering/libvirt,andreabolognani/libvirt,olafhering/libvirt,crobinso/libvirt,jardasgit/libvirt