Add a statechange notify zedlet

Now that ZED has internal fault diagnosis and the statechange event
is generated for faulted states, we can replace the io-notify and
checksum-notify zedlets with one based on statechange.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@intel.com>
Closes #5383

cmd/zed/Makefile.am

@@ -61,23 +61,21 @@ zedexecdir = $(libexecdir)/zfs/zed.d
 dist_zedexec_SCRIPTS = \
 	zed.d/all-debug.sh \
 	zed.d/all-syslog.sh \
-	zed.d/checksum-notify.sh \
 	zed.d/data-notify.sh \
 	zed.d/generic-notify.sh \
-	zed.d/io-notify.sh \
 	zed.d/resilver_finish-notify.sh \
 	zed.d/scrub_finish-notify.sh \
 	zed.d/statechange-led.sh \
+	zed.d/statechange-notify.sh \
 	zed.d/vdev_clear-led.sh
 
 zedconfdefaults = \
 	all-syslog.sh \
-	checksum-notify.sh \
 	data-notify.sh \
-	io-notify.sh \
 	resilver_finish-notify.sh \
 	scrub_finish-notify.sh \
 	statechange-led.sh \
+	statechange-notify.sh \
 	vdev_clear-led.sh
 
 install-data-hook: