Description: Update AM_INIT_AUTOMAKE to use subdir-objects
With this option, the objects are placed into the subdirectory of
the build directory corresponding to the subdirectory of the source file.
Fixes this warning:

Makefile.am:103: warning: source file 'src/ibdiag_common.c' is in a subdirectory,
Makefile.am:103: but option 'subdir-objects' is disabled
automake: warning: possible forward-incompatibility.
automake: At least a source file is in a subdirectory, but the 'subdir-objects'
automake: automake option hasn't been enabled.  For now, the corresponding output
automake: object file(s) will be placed in the top-level directory.  However,
automake: this behaviour will change in future Automake versions: they will
automake: unconditionally cause object files to be placed in the same subdirectory
automake: of the corresponding sources.
automake: You are advised to start using 'subdir-objects' option throughout your
automake: project, to avoid future incompatibilities.

Author: Ana Guerrero Lopez <ana@debian.org>
Last-Update: 2016-09-04

--- a/configure.ac
+++ b/configure.ac
@@ -5,7 +5,8 @@
 AC_CONFIG_AUX_DIR(config)
 AC_CONFIG_MACRO_DIR(config)
 AM_CONFIG_HEADER(config.h)
-AM_INIT_AUTOMAKE([foreign])
+#AM_INIT_AUTOMAKE([foreign])
+AM_INIT_AUTOMAKE([subdir-objects])
 
 AC_SUBST(RELEASE, ${RELEASE:-unknown})
 AC_SUBST(TARBALL, ${TARBALL:-${PACKAGE}-${VERSION}.tar.gz})
