remove type command

The posix equivalent of the type command is "command -v", so now we use
that. Thanks to Jonathan Callen <jcallen@gentoo.org> for informing me
wrt the fix.

sh/rc-mount.sh

@@ -40,7 +40,7 @@ do_unmount()
 
 		retry=4 # Effectively TERM, sleep 1, TERM, sleep 1, KILL, sleep 1
 		while ! LC_ALL=C $cmd "$mnt" 2>/dev/null; do
-			if type fuser >/dev/null 2>&1; then
+			if command -v fuser >/dev/null 2>&1; then
 				pids="$(timeout -k 10 -s KILL "${rc_fuser_timeout:-60}" \
 					fuser $f_opts "$mnt" 2>/dev/null)"
 			fi