[PATCH] Fix warning from latest GCC in tst-printf.c

[Joseph Myers]

On Tue, 1 Nov 2016, Steve Ellcey wrote:

> Ping.  One of the snprintf statements in this test is using a %.999999u
> format so it is obvious that the test wants to test formats that would
> go beyond the limit of the snprintf buffer and so we should ignore the
> warnings in this test.

OK provided you've tested that this change works with older GCC that lack 
the new option (otherwise it would need to be conditional on the GCC 
version).

-- 
Joseph S. Myers
joseph@codesourcery.com