Remove a use of is_mi_like_p from darwin-nat-info.c

This removes a use of is_mi_like_p from darwin-nat-info.c.
This is not needed because MI already ignores ui_out::text.

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

	* darwin-nat-info.c (darwin_debug_regions_recurse): Remove use of
	is_mi_like_p.