net: fix warnings in 'make htmldocs' by moving macro definition out of field declaration

Docbook does not like the definition of macros inside a field declaration
and adds a warning. Move the definition out.

Fixes: 79462ad02e86180 ("net: add validation for the socket syscall protocol argument")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -403,8 +403,8 @@ struct sock {
 				sk_no_check_rx : 1,
 				sk_userlocks : 4,
 				sk_protocol  : 8,
-#define SK_PROTOCOL_MAX U8_MAX
 				sk_type      : 16;
+#define SK_PROTOCOL_MAX U8_MAX
 	kmemcheck_bitfield_end(flags);
 	int			sk_wmem_queued;
 	gfp_t			sk_allocation;