[PATCH 3/9] Use SCANF_ISOC99_A instead of _IO_FLAGS2_SCANF_STD.

[Gabriel F. T. Gomes]

On Wed, 07 Mar 2018, Zack Weinberg wrote:

>Change the callers of __vfscanf_internal and __vfwscanf_internal that
>want C99-compliant behavior to communicate this via the new flags
>argument, rather than setting bits on the FILE object.  This also
>means these functions do not need to do their own locking.

Looks good to me.