Move root option processing into a pre-mount hook.

This will make it easier to add support for root on nfs, root on iscsi,
root on multipath, and other such oddities.

modules.d/99base/install

@@ -3,6 +3,7 @@ dracut_install mount mknod mkdir modprobe pidof sleep chroot echo sed sh ls
 # install our scripts and hooks
 inst "$moddir/init" "/init"
 inst "$moddir/switch_root" "/sbin/switch_root"
+inst_hook pre-mount 10 "$moddir/parse-root-opts.sh"
 inst_hook pre-pivot 50 "$moddir/selinux-loadpolicy.sh"
 inst_hook mount 90 "$moddir/resume.sh"
-inst_hook mount 99 "$moddir/mount-partition.sh"
+inst_hook mount 99 "$moddir/mount-root.sh"

modules.d/99base/mount-root.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+[ "$root" ] && mount $fstype -o "$rflags" "$root" "$NEWROOT" && \
+    ROOTFS_MOUNTED=yes

modules.d/99base/parse-root-opts.sh

@@ -22,6 +22,3 @@
 [ "$fstype" ] || {
     fstype="$(getarg rootfstype=)" && fstype="-t ${fstype}"
 }
-
-[ -e "$root" ] && mount $fstype -o "$rflags" "$root" "$NEWROOT" && \
-    ROOTFS_MOUNTED=yes