netfilter: nftables: Add __printf() attribute

nft_request_module calls vsnprintf() using parameters passed to it.
Make the function with __printf() attribute so the compiler can check
the format and arguments.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 file changed