various: update links to usr-merge

README

@@ -270,8 +270,8 @@ REQUIREMENTS:
         longer supported, and moving everything under /usr/ is required. Systems
         with a separate /usr/ partition must mount it before transitioning into it
         (i.e.: from the initrd). For more information see:
-        https://www.freedesktop.org/wiki/Software/systemd/separate-usr-is-broken
-        https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge
+        https://systemd.io/SEPARATE_USR_IS_BROKEN
+        https://systemd.io/THE_CASE_FOR_THE_USR_MERGE
 
         Additional packages are necessary to run some tests:
         - nc                 (used by test/TEST-12-ISSUE-3171)

man/org.freedesktop.systemd1.xml

@@ -1660,9 +1660,8 @@ node /org/freedesktop/systemd1 {
           <listitem><para><filename>/bin</filename>, <filename>/sbin</filename> and
           <filename>/lib*</filename> are not symlinks to their counterparts under <filename>/usr/</filename>.
           For more information on this issue consult
-          <ulink url="https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge">
-            The Case for the /usr Merge
-          </ulink>.</para>
+          <ulink url="https://systemd.io/THE_CASE_FOR_THE_USR_MERGE">The Case for the /usr Merge</ulink>.
+          </para>
 
           <xi:include href="version-info.xml" xpointer="v252"/></listitem>
         </varlistentry>

src/core/main.c

@@ -1371,7 +1371,7 @@ static void test_usr(void) {
 
         log_warning("/usr appears to be on its own filesystem and is not already mounted. This is not a supported setup. "
                     "Some things will probably break (sometimes even silently) in mysterious ways. "
-                    "Consult https://www.freedesktop.org/wiki/Software/systemd/separate-usr-is-broken for more information.");
+                    "Consult https://systemd.io/SEPARATE_USR_IS_BROKEN for more information.");
 }
 
 static int enforce_syscall_archs(Set *archs) {