The version of mount.c that driver_current.patch was created against predates the re-introduction of smbfs in r252356. As a result, the patch will fail on that file. As 10-STABLE was forked following this revision, both 10-STABLE and 11-CURRENT no longer build against this patch. It should be a simple fix to add "smbfs" before "udf" in the fs array in the patch file to correct for this.
(It might theoretically be worth adding a reference to mount_udf2 in mount.8 as well, but that's not really all that important)