init.d/root: also remount / with options provided in /etc/fstab

Without this commit, the root OpenRC service remounts all mounted
filesystems (except /) with the options defined in /etc/fstab via
fstabinfo. It is presently unclear to me why / was excluded from
remounting in 497ff7ee41168d863971efb52e2ca6b42f765832 and unfortunately
neither the commit nor the associated Bugzilla issue [1] provides
further information on this.

At Alpine, our initramfs does currently not remount / with all options
defined in /etc/fstab [2]. As part of the discussion on the Alpine side
of things we wondered why OpenRC does not remount / since this would be
the easier solution for us. For this reason, this commit changes the
behavior of the OpenRC root services accordingly to also remount / with
the options defined in /etc/fstab.

[1]: https://bugs.gentoo.org/401573
[2]: https://gitlab.alpinelinux.org/alpine/mkinitfs/-/merge_requests/103
This fixes #533.

init.d/root.in

@@ -48,14 +48,8 @@ start()
 	ebegin "Remounting filesystems"
 	local mountpoint
 	for mountpoint in $(fstabinfo); do
-		case "${mountpoint}" in
-			/)
-			;;
-			/*)
-				mountinfo -q "${mountpoint}" && \
-					fstabinfo --remount "${mountpoint}"
-			;;
-		esac
+		mountinfo -q "${mountpoint}" && \
+			fstabinfo --remount "${mountpoint}"
 	done
 	eend 0
 }