util-linux: Drop required version back to v2.27.1

It was bumped in a40d934007 but this
is hardly load bearing stuff so let's document the version we actually
require rather than the version that makes a hardly load bearing feature
work properly, especially since v2.41 is extremely new and requiring
distributions to have that is just unrealistic.

This doesn't actually change anything materially except documentation,
but it keeps us honest about depending on stuff from newer util-linux
because we happen to document reliance on an extremely new version.

README

@@ -264,9 +264,9 @@ REQUIREMENTS:
         During runtime, you need the following additional
         dependencies:
 
-        util-linux >= v2.41 required (including but not limited to: mount,
-                                      umount, swapon, swapoff, sulogin,
-                                      agetty, fsck)
+        util-linux >= v2.27.1 required (including but not limited to: mount,
+                                        umount, swapon, swapoff, sulogin,
+                                        agetty, fsck)
         dbus >= 1.4.0 (strictly speaking optional, but recommended)
                 NOTE: If using dbus < 1.9.18, you should override the default
                 policy directory (--with-dbuspolicydir=/etc/dbus-1/system.d).