There are three cases where vir*DeviceGetPath() returns a const
string. In these cases, the string is initialized in
corresponding vir*DeviceNew() calls which fail if string couldn't
be allocated. There's no point in checking the second time if the
string is NULL.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>