[IPV4]: Make struct in_addr::s_addr __be32

There will be relatively small increase in sparse endian warnings, but
this (and sin_port) patch is a first step to make networking code
endian clean.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/in.h

@@ -52,7 +52,7 @@ enum {
 
 /* Internet address. */
 struct in_addr {
-	__u32	s_addr;
+	__be32	s_addr;
 };
 
 #define IP_TOS		1