fix(xcat-core): the el10 Genesis image gives root the home directory /root

Every case that boots a node into the el10 legacy Genesis image fails with
"root@<cn>: Permission denied (publickey,password,keyboard-interactive)".
mknb writes the management node key to /.ssh/authorized_keys, and sshd looks
for it under the home directory of root.

The dracut cmdline hook deletes the root entry the image ships with
"sed -i '/^root:x/d'" and appends its own entry with the home directory /.
dracut 99base writes that entry, and from dracut 060 the password field holds
x only when the image is built --hostonly. The Genesis image is built with -N,
so el10 (dracut 107) ships "root::0:0::/root:/bin/sh". The delete does not
match, two root entries survive, and getpwnam returns the first one. el8
(dracut 049) and el9 (dracut 057) always ship the x and are not affected.

The delete now matches the user name only. All three cmdline hooks carry the
same statement and all three change.

genesis_root_home.t runs the rewrite against both entry shapes and fails on
the empty password field without this change.

Signed-off-by: Daniel Hilst <392820+dhilst@users.noreply.github.com>

xCAT-genesis-builder/dracut_105/el/xcat-cmdline.sh

@@ -22,7 +22,9 @@ echo PS1="'"'[xCAT Genesis running on \H \w]\$ '"'" > /.bash_profile
 mkdir -p /etc/ssh
 mkdir -p /var/tmp/
 mkdir -p /var/empty/sshd
-sed -i '/^root:x/d' /etc/passwd
+# dracut writes this entry itself, with an empty password field unless the image is
+# built --hostonly. Match the user name only.
+sed -i '/^root:/d' /etc/passwd
 cat >>/etc/passwd <<"__ENDL"
 root:x:0:0::/:/bin/bash
 sshd:x:30:30:SSH User:/var/empty/sshd:/sbin/nologin

xCAT-genesis-builder/dracut_105/ubuntu/xcat-cmdline.sh

@@ -22,7 +22,9 @@ echo PS1="'"'[xCAT Genesis running on \H \w]\$ '"'" > /.bash_profile
 mkdir -p /etc/ssh
 mkdir -p /var/tmp/
 mkdir -p /var/empty/sshd
-sed -i '/^root:x/d' /etc/passwd
+# dracut writes this entry itself, with an empty password field unless the image is
+# built --hostonly. Match the user name only.
+sed -i '/^root:/d' /etc/passwd
 cat >>/etc/passwd <<"__ENDL"
 root:x:0:0::/:/bin/bash
 sshd:x:30:30:SSH User:/var/empty/sshd:/sbin/nologin

xCAT-genesis-builder/xcat-cmdline.sh

@@ -8,7 +8,9 @@ echo PS1="'"'[xCAT Genesis running on \H \w]\$ '"'" > /.bash_profile
 mkdir -p /etc/ssh
 mkdir -p /var/tmp/
 mkdir -p /var/empty/sshd
-sed -i '/^root:x/d' /etc/passwd
+# dracut writes this entry itself, with an empty password field unless the image is
+# built --hostonly. Match the user name only.
+sed -i '/^root:/d' /etc/passwd
 cat >>/etc/passwd <<"__ENDL"
 root:x:0:0::/:/bin/bash
 sshd:x:30:30:SSH User:/var/empty/sshd:/sbin/nologin