autoconf: use include directives instead of recursing down contrib

Also make the pyzfs build actually out-of-tree and quiet by default

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Rapptz <rapptz@gmail.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13316

contrib/initramfs/scripts/Makefile.am

@@ -1,12 +0,0 @@
-include $(top_srcdir)/config/Shellcheck.am
-
-scriptsdir = /usr/share/initramfs-tools/scripts
-
-dist_scripts_SCRIPTS = \
-	zfs
-
-SUBDIRS = local-top
-
-SHELLCHECKDIRS = $(SUBDIRS)
-SHELLCHECK_SHELL = sh
-SHELLCHECKSCRIPTS += $(dist_scripts_SCRIPTS)

contrib/initramfs/scripts/local-top/Makefile.am

@@ -1,8 +0,0 @@
-include $(top_srcdir)/config/Shellcheck.am
-
-localtopdir = /usr/share/initramfs-tools/scripts/local-top
-
-dist_localtop_SCRIPTS = \
-	zfs
-
-SHELLCHECKSCRIPTS += $(dist_scripts_SCRIPTS)