ktest: Restore stty setting at first in dodie

The do_send_email() will call die before restoring stty if sendmail
setting is not correct or sendmail is not installed. It is safer to
restore it in the beginning of dodie().

Link: https://lkml.kernel.org/r/167420617635.2988775.13045295332829029437.stgit@devnote3



Cc: John 'Warthog9' Hawley <warthog9@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>