Ktest: add email options to sample.config

A block of email options is added under the optional config section.

Link: http://lkml.kernel.org/r/1522094884-22718-5-git-send-email-tianyang.chen@oracle.comSuggested-by: NDhaval Giani <dhaval.giani@oracle.com>
Signed-off-by: NTim Tianyang Chen <tianyang.chen@oracle.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

tools/testing/ktest/sample.conf

@@ -401,6 +401,28 @@
 
 #### Optional Config Options (all have defaults) ####
 
+# Email options for receiving notifications. Users must setup
+# the specified mailer prior to using this feature.
+#
+# (default undefined)
+#MAILTO =
+#
+# Supported mailers: sendmail, mail, mailx
+# (default sendmail)
+#MAILER = sendmail
+#
+# Errors are defined as those would terminate the script
+# (default 1)
+#EMAIL_ON_ERROR = 1
+# (default 1)
+#EMAIL_WHEN_FINISHED = 1
+# (default 0)
+#EMAIL_WHEN_STARTED = 1
+#
+# Users can cancel the test by Ctrl^C
+# (default 0)
+#EMAIL_WHEN_CANCELED = 1
+
 # Start a test setup. If you leave this off, all options
 # will be default and the test will run once.
 # This is a label and not really an option (it takes no value).