Remove some uses of is_mi_like_p from py-framefilter.c

Remove some uses of is_mi_like_p from py-framefilter.c

Some uses of is_mi_like_p in py-framefilter.c were not needed.  In
general a call to ui_out::text, ui_out::message, or ui_out::spaces
does not need to be guarded -- these are already ignored by MI.

ChangeLog
2018-04-30  Tom Tromey  <tom@tromey.com>

	* python/py-framefilter.c (py_print_single_arg)
	(enumerate_locals, py_print_args, py_print_frame): Remove some
	uses of is_mi_like_p.