docs: Fix ./configure following c/s d661611

The misc/xen-command-line.markdown reference in configure.ac should have been
updated in the same changeset.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

docs/configure

@@ -584,7 +584,7 @@ PACKAGE_STRING='Xen Hypervisor Documentation 4.12'
 PACKAGE_BUGREPORT='xen-devel@lists.xen.org'
 PACKAGE_URL='http://www.xen.org/'
 
-ac_unique_file="misc/xen-command-line.markdown"
+ac_unique_file="misc/xen-command-line.pandoc"
 ac_subst_vars='LTLIBOBJS
 LIBOBJS
 PERL

docs/configure.ac

@@ -4,7 +4,7 @@
 AC_PREREQ([2.67])
 AC_INIT([Xen Hypervisor Documentation], m4_esyscmd([../version.sh ../xen/Makefile]),
     [xen-devel@lists.xen.org], [xen], [http://www.xen.org/])
-AC_CONFIG_SRCDIR([misc/xen-command-line.markdown])
+AC_CONFIG_SRCDIR([misc/xen-command-line.pandoc])
 AC_CONFIG_FILES([
 ../config/Docs.mk
 man/xl.cfg.5.pod