io_uring/net: refactor io_sr_msg types

In preparation for using struct io_sr_msg for zerocopy sends, clean up
types. First, flags can be u16 as it's provided by the userspace in u16
ioprio, as well as addr_len. This saves us 4 bytes. Also use unsigned
for size and done_io, both are as well limited to u32.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/42c2639d6385b8b2181342d2af3a42d3b1c5bcd2.1662639236.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/net.c

@@ -55,21 +55,21 @@ struct io_sr_msg {
 		struct user_msghdr __user	*umsg;
 		void __user			*buf;
 	};
+	unsigned			len;
+	unsigned			done_io;
 	unsigned			msg_flags;
-	unsigned			flags;
-	size_t				len;
-	size_t				done_io;
+	u16				flags;
 };
 
 struct io_sendzc {
 	struct file			*file;
 	void __user			*buf;
-	size_t				len;
+	unsigned			len;
+	unsigned			done_io;
 	unsigned			msg_flags;
-	unsigned			flags;
-	unsigned			addr_len;
+	u16				flags;
+	u16				addr_len;
 	void __user			*addr;
-	size_t				done_io;
 	struct io_kiocb 		*notif;
 };