Add SMART self-test results to zpool status -c

Add in SMART self-test results to zpool status|iostat -c.  This
works for both SAS and SATA drives.

Also, add plumbing to allow the 'smart' script to take smartctl
output from a directory of output text files instead of running
it against the vdevs.

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #7178

cmd/zpool/Makefile.am

@@ -62,7 +62,12 @@ dist_zpoolexec_SCRIPTS = \
 	zpool.d/nvme_err \
 	zpool.d/pwr_cyc \
 	zpool.d/upath \
-	zpool.d/vendor
+	zpool.d/vendor \
+	zpool.d/smart_test \
+	zpool.d/test_type \
+	zpool.d/test_status \
+	zpool.d/test_progress \
+	zpool.d/test_ended
 
 zpoolconfdefaults = \
 	enc \
@@ -101,7 +106,12 @@ zpoolconfdefaults = \
 	nvme_err \
 	pwr_cyc \
 	upath \
-	vendor
+	vendor \
+	smart_test \
+	test_type \
+	test_status \
+	test_progress \
+	test_ended
 
 install-data-hook:
 	$(MKDIR_P) "$(DESTDIR)$(zpoolconfdir)"