Fixes for su on freebsd

Addresses multiple issues when using su on freebsd including
* su prompt differs between platforms, so turned that check into a
  regex comparison instead of a simple string comparison
* not using '-c' after su causes problems, so added that for all
  platforms
* fixed quoting issues due to multiple uses of '-c' introduced by
  the above fix

Fixes #7503
Fixes #7507

lib/ansible/runner/connection_plugins/ssh.py

@@ -17,6 +17,7 @@
 #
 
 import os
+import re
 import subprocess
 import shlex
 import pipes
@@ -268,6 +269,7 @@ class Connection(object):
 
         if su and su_user:
             sudocmd, prompt, success_key = utils.make_su_cmd(su_user, executable, cmd)
+            prompt_re = re.compile(prompt)
             ssh_cmd.append(sudocmd)
         elif not self.runner.sudo or not sudoable:
             prompt = None
@@ -308,7 +310,12 @@ class Connection(object):
             sudo_output = ''
             sudo_errput = ''
 
-            while not sudo_output.endswith(prompt) and success_key not in sudo_output:
+            while True:
+                if success_key in sudo_output or \
+                    (self.runner.sudo_pass and sudo_output.endswith(prompt)) or \
+                    (self.runner.su_pass and prompt_re.match(sudo_output)):
+                    break
+
                 rfd, wfd, efd = select.select([p.stdout, p.stderr], [],
                                               [p.stdout], self.runner.timeout)
                 if p.stderr in rfd: