initramfs: move qubes_cow_setup hook to pre-trigger

This hook require new device nodes to appear in /dev. If devtmpfs is
used, it's not a problem ("simple" initramfs case), but otherwise udevd
is needed - and it isn't running in pre-udev hook yet.

QubesOS/qubes-issues#2577

dracut/full-dmroot/module-setup.sh

@@ -14,7 +14,7 @@ depends() {
 }
 
 install() {
-    inst_hook pre-udev 90 $moddir/qubes_cow_setup.sh
+    inst_hook pre-trigger 90 $moddir/qubes_cow_setup.sh
     inst_multiple \
         sfdisk \
         mkswap

dracut/full-dmroot/qubes_cow_setup.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# This file should be placed in pre-mount directory in dracut's initramfs, or
+# This file should be placed in pre-trigger directory in dracut's initramfs, or
 # scripts/local-top in case of initramfs-tools
 #
 

dracut/simple/init.sh

@@ -87,7 +87,6 @@ if ! [ -d "$NEWROOT/lib/modules/$kver/kernel" ]; then
     rmdir /tmp/modules
 fi
 
-
 umount /dev /sys /proc
 
 exec switch_root $NEWROOT /sbin/init