Update kernel version to 5.12 in tst-mman-consts.py

[Florian Weimer]

* Joseph Myers:

> This patch updates the kernel version in the test tst-mman-consts.py
> to 5.12.  (There are no new MAP_* constants covered by this test in
> 5.12 that need any other header changes.)
>
> Tested with build-many-glibcs.py.
>
> diff --git a/sysdeps/unix/sysv/linux/tst-mman-consts.py b/sysdeps/unix/sysv/linux/tst-mman-consts.py
> index 43c6f98126..fec7c9b8da 100644
> --- a/sysdeps/unix/sysv/linux/tst-mman-consts.py
> +++ b/sysdeps/unix/sysv/linux/tst-mman-consts.py
> @@ -33,7 +33,7 @@ def main():
>                          help='C compiler (including options) to use')
>      args = parser.parse_args()
>      linux_version_headers = glibcsyscalls.linux_kernel_version(args.cc)
> -    linux_version_glibc = (5, 11)
> +    linux_version_glibc = (5, 12)
>      sys.exit(glibcextract.compare_macro_consts(
>          '#define _GNU_SOURCE 1\n'
>          '#include <sys/mman.h>\n',

Looks okay, thanks.

Florian