syscalls: fix syscall macros for newfstat/newfstatat

The __NR_newfstat and __NR_newfstatat macros accidentally got renamed
in the conversion to the syscall.tbl format, dropping the 'new' portion
of the name.

In an unrelated change, the two syscalls are no longer architecture
specific but are once more defined on all 64-bit architectures, so the
'newstat' ABI keyword can be dropped from the table as a simplification.

Fixes: Fixes: 4fe53bf2 ("syscalls: add generic scripts/syscall.tbl")
Closes: https://lore.kernel.org/lkml/838053e0-b186-4e9f-9668-9a3384a71f23@app.fastmail.com/T/#t


Reported-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>