man: drop whitespace from final <programlisting> lines

In the troff output, this doesn't seem to make any difference. But in the
html output, the whitespace is sometimes preserved, creating an additional
gap before the following content. Drop it everywhere to avoid this.

man/pam_systemd_loadkey.xml

@@ -119,14 +119,14 @@
 -auth       optional    pam_gnome_keyring.so
 -session    optional    pam_gnome_keyring.so auto_start
 -session    optional    pam_kwallet5.so auto_start
-    </programlisting>
+</programlisting>
 
     <para>And add the following lines to your display manager's systemd service file, so it can access root's keyring:</para>
 
     <programlisting>
 [Service]
 KeyringMode=inherit
-    </programlisting>
+</programlisting>
 
     <para>In this setup, early during the boot process,
     <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>