Do not include AC_CONFIG_FILES in BUILT_SOURCES

BUILT_SOURCES is used to trigger early generation of files in the `make`
process to workaround dependency problems:

    https://www.gnu.org/software/automake/manual/html_node/Sources.html

AC_CONFIG_FILES are generated by `configure`, so they are already
present in the file system even before `make` is called. Furthermore,
AC_CONFIG_FILES already properly handle dist and clean targets, so no
need to add them to EXTRA_DIST or DISTCLEANFILES:

    https://www.gnu.org/software/automake/manual/html_node/Requirements.html

examples/Makefile.am

@@ -66,10 +66,4 @@ DIST_SUBDIRS = \
 	xenomai \
 	xenomai_posix
 
-EXTRA_DIST = \
-	Kbuild.in
-
-BUILT_SOURCES = \
-	Kbuild
-
 #------------------------------------------------------------------------------

examples/dc_rtai/Makefile.am

@@ -30,12 +30,8 @@
 #------------------------------------------------------------------------------
 
 EXTRA_DIST = \
-	Kbuild.in \
 	dc_rtai_sample.c
 
-BUILT_SOURCES = \
-	Kbuild
-
 modules:
 	$(MAKE) -C "$(LINUX_SOURCE_DIR)" M="@abs_srcdir@" modules
 

examples/mini/Makefile.am

@@ -32,12 +32,8 @@
 #------------------------------------------------------------------------------
 
 EXTRA_DIST = \
-	Kbuild.in \
 	mini.c
 
-BUILT_SOURCES = \
-	Kbuild
-
 modules:
 	$(MAKE) -C "$(LINUX_SOURCE_DIR)" M="@abs_srcdir@" modules
 

examples/rtai/Makefile.am

@@ -30,12 +30,8 @@
 #------------------------------------------------------------------------------
 
 EXTRA_DIST = \
-	Kbuild.in \
 	rtai_sample.c
 
-BUILT_SOURCES = \
-	Kbuild
-
 modules:
 	$(MAKE) -C "$(LINUX_SOURCE_DIR)" M="@abs_srcdir@" modules
 

examples/tty/Makefile.am

@@ -36,12 +36,6 @@ noinst_HEADERS = \
 	serial.h \
 	tty.c
 
-EXTRA_DIST = \
-	Kbuild.in
-
-BUILT_SOURCES = \
-	Kbuild
-
 modules:
 	$(MAKE) -C "$(LINUX_SOURCE_DIR)" M="@abs_srcdir@" modules