your subject was a little misleading to me, I really thought you wanted to fsck a remote fs.
Well I think cifs is available on MOST linux systems, but it is often there as a module. You could check by the following procedure:
grep -q cifs /proc/filesystems && HAVE_CIFS=yes
/sbin/modinfo cifs &>/dev/null && HAVE_CIFS=yes
if [ "x$HAVE_CIFS" = "xyes" ]; then
The first line checks whether cifs is currently available as filesystem, the second line checks whether the loadable kernel module is there -- in both cases, cifs will be usable on this box.