util: Remove invalid parameter checks from virAuthGet{Username|Password}
util: Remove invalid parameter checks from virAuthGet{Username|Password}

Now that the virAuthGet*Path helpers make the checks, we can remove
them from here.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>
Reviewed-by: Marcos Paulo de Souza <0b4ebe3a213a49a2bc3457b98408e6d86812eb46@gmail.com>

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