Remove libm-test.inc comment listing functions tested and not tested.

math/libm-test.inc has a comment listing the functions tested and not
tested.  The list of functions tested duplicates what is immediately
obvious from the rest of the file and adds another place to update
when adding a function.  I've put the information about functions not
tested on the wiki todo list; this patch removes that comment, in
preparation for splitting tests of each function into separate .inc
files with common code staying in a separate .c file.

Tested for x86_64.

	* math/libm-test.inc: Remove comment listing functions tested and
	not tested.