Add subdir-objects option to automake (#386)

Reason:
auparse/Makefile.am:92: warning: source file '../lib/gen_tables.c' is in a subdirectory,
auparse/Makefile.am:92: but option 'subdir-objects' is disabled
automake-1.16: warning: possible forward-incompatibility.
automake-1.16: At least one source file is in a subdirectory, but the 'subdir-objects'
automake-1.16: automake option hasn't been enabled.  For now, the corresponding output
automake-1.16: object file(s) will be placed in the top-level directory.  However, this
automake-1.16: behavior may change in a future Automake major version, with object
automake-1.16: files being placed in the same subdirectory as the corresponding sources.
automake-1.16: You are advised to start using 'subdir-objects' option throughout your
automake-1.16: project, to avoid future incompatibilities.

Author: Cropi

configure.ac

@@ -38,7 +38,7 @@ echo Configuring auditd $VERSION
 
 AC_CONFIG_MACRO_DIR([m4])
 AC_CANONICAL_TARGET
-AM_INIT_AUTOMAKE
+AM_INIT_AUTOMAKE([subdir-objects])
 LT_INIT
 AC_SUBST(LIBTOOL_DEPS)
 OLDLIBS="$LIBS"
@@ -123,7 +123,7 @@ AC_MSG_RESULT($DEALLOC)
 
 dnl; pthread_yield is used in zos-remote
 OLDLIBS="$LIBS"
-AC_SEARCH_LIBS(pthread_yield, pthread, 
+AC_SEARCH_LIBS(pthread_yield, pthread,
 	[AC_DEFINE(HAVE_PTHREAD_YIELD, 1, [Define to 1 if we have pthread_yield])], [])
 LIBS="$OLDLIBS"