configure: Fixed a typo: code snippet outside AC_CHECK_HEADERS macro.
diff --git a/configure.ac b/configure.ac
index 92c763e..199e2bb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -281,10 +281,10 @@
     [#include <sys/types.h>
      #if HAVE_SYS_SOCKET_H
      # include <sys/socket.h>
-     #endif])
+     #endif
      #if HAVE_SYS_SOCKETVAR_H
      # include <sys/socketvar.h>
-     #endif
+     #endif])
 
 AC_CHECK_HEADERS([netinet/tcp_var.h],,,
     [#include <sys/types.h>