filesystem targets: disable default dependencies

This means we can use default dependencies on mount units without having to get them automatically
ordered before the filesystem targets.

Reported-by: Thomas Baechler <thomas@archlinux.org>

units/initrd-fs.target

@@ -12,3 +12,5 @@ OnFailure=emergency.target
 OnFailureIsolate=yes
 ConditionPathExists=/etc/initrd-release
 After=initrd-parse-etc.service
+DefaultDependencies=no
+Conflicts=shutdown.target

units/initrd-root-fs.target

@@ -11,3 +11,5 @@ Documentation=man:systemd.special(7)
 ConditionPathExists=/etc/initrd-release
 OnFailure=emergency.target
 OnFailureIsolate=yes
+DefaultDependencies=no
+Conflicts=shutdown.target

units/local-fs.target

@@ -9,5 +9,7 @@
 Description=Local File Systems
 Documentation=man:systemd.special(7)
 After=local-fs-pre.target
+DefaultDependencies=no
+Conflicts=shutdown.target
 OnFailure=emergency.target
 OnFailureIsolate=no

units/remote-fs.target

@@ -9,6 +9,8 @@
 Description=Remote File Systems
 Documentation=man:systemd.special(7)
 After=remote-fs-pre.target
+DefaultDependencies=no
+Conflicts=shutdown.target
 
 [Install]
 WantedBy=multi-user.target