[TestCompletion] Spawn LLDB with '--no-use-colors'.

[sivachandra]

Summary

TestCompletion was broken for Ubuntu (and probably for Debian also).
The issue was that the lldb prompt in color (which is the default
behavior) was confusing pexpect.

[sivachandra]

I will put this in by EoD if there are no comments.

[clayborg]

Looks good.

test/functionalities/completion/TestCompletion.py

def complete_from_to(self, str_input, patterns, turn_off_re_match=False):
         # later on.
         if not isinstance(patterns, list):
             patterns = [patterns]
         
         # The default lldb prompt.
         prompt = "(lldb) "
 
         # So that the child gets torn down after the test.
-        self.child = pexpect.spawn('%s %s' % (self.lldbHere, self.lldbOption))
+        self.child = pexpect.spawn(self.lldbHere,
+                                   [self.lldbOption] + ['--no-use-colors'])
         child = self.child
         # Turn on logging for input/output to/from the child.
         with open('child_send.txt', 'w') as f_send:
             with open('child_read.txt', 'w') as f_read:
                 child.logfile_send = f_send
                 child.logfile_read = f_read
 
                 child.expect_exact(prompt)