build: do not call boilerplate ourself

Rationale see section 3.5 "Using `autoreconf' to Update `configure'
Scripts" of the autoconf manual.

http://www.gnu.org/software/autoconf/manual/autoconf-2.67/html_node/autoreconf-Invocation.html

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

Makefile.am

@@ -1,3 +1,6 @@
+
+ACLOCAL_AMFLAGS = -I config
+
 include $(top_srcdir)/config/rpm.am
 include $(top_srcdir)/config/deb.am
 include $(top_srcdir)/config/tgz.am

autogen.sh

@@ -1,7 +1,4 @@
 #!/bin/sh
 
-aclocal -I config
-libtoolize --automake --copy
-autoheader
-automake --add-missing --include-deps --copy
-autoconf
+autoreconf -fiv
+rm -Rf autom4te.cache

config/.gitignore

@@ -4,3 +4,5 @@
 /install-sh
 /ltmain.sh
 /missing
+/libtool.m4
+/lt*.m4

configure.ac

@@ -34,6 +34,7 @@ AC_INIT
 AC_LANG(C)
 ZFS_AC_META
 AC_CONFIG_AUX_DIR([config])
+AC_CONFIG_MACRO_DIR([config])
 AC_CANONICAL_SYSTEM
 AM_MAINTAINER_MODE
 AM_SILENT_RULES