Fix tests in configure.ac

We accidentally had a single AS_IF where multiple ones were required.

Fixes: ff052d0 ("Don't try to build manpages without docbook2man")
Signed-off-by: Wouter Verhelst <[email protected]>

configure.ac

@@ -324,21 +324,26 @@ else
 	AC_DEFINE(HAVE_NETLINK, 0, [Define to 1 if we have netlink support])
 fi
 
+AC_MSG_CHECKING([whether man pages are requested])
 AC_ARG_ENABLE([manpages],
 	AS_HELP_STRING([--disable-manpages], [Do not install man pages]),
 	[],
 	[: m4_divert_text([DEFAULTS], [enable_manpages=check])]
 )
+AC_MSG_RESULT([$enable_manpages])
 
 AS_IF([test "x$enable_manpages" != "xno"], [
        AC_CHECK_PROG([DB2M], docbook2man, [docbook2man])
-	],
-      [test "x$enable_manpages" = "xyes" -a "x$DB2M" = "x"], [
+	])
+AS_IF([test "x$enable_manpages" = "xyes" -a "x$DB2M" = "x"], [
        AC_MSG_ERROR([docbook2man not found, but is required to build manpages])
-	]
-      [test "x$DB2M" != "x"], [enable_manpages=yes])
+	],
+      [test "x$DB2M" != "x"], [enable_manpages=yes],
+       [AC_MSG_ERROR([don't know what to do here])])
+AC_MSG_CHECKING([whether to build manpages])
+AC_MSG_RESULT([$enable_manpages])
 
-AM_CONDITIONAL(MANPAGES, test "x$enable_manpages" = "xyes"])
+AM_CONDITIONAL(MANPAGES, test "x$enable_manpages" = "xyes")
 AS_IF([test "x$enable_manpages" != "xno"], [
 	AC_SUBST([MAN_CONFIG_FILES],["\
 		man/nbd-client.8.sgml \