Buildkernel failure (error: declaration of 'struct socket' will not be visible outside of this function)

Hi

In file included from /usr/src/sys/netpfil/pf/pfsync_nv.c:38:
/usr/src/sys/netinet6/ip6_var.h:380:28: error: declaration of 'struct 
socket' will not be visible outside of this function [-Werror,-Wvisibility]
   380 | int     icmp6_ctloutput(struct socket *, struct sockopt *sopt);
       |                                ^
/usr/src/sys/netinet6/ip6_var.h:409:26: error: declaration of 'struct 
socket' will not be visible outside of this function [-Werror,-Wvisibility]
   409 | int     ip6_ctloutput(struct socket *, struct sockopt *);
       |                              ^
/usr/src/sys/netinet6/ip6_var.h:410:30: error: declaration of 'struct 
socket' will not be visible outside of this function [-Werror,-Wvisibility]
   410 | int     ip6_raw_ctloutput(struct socket *, struct sockopt *);
       |                                  ^
/usr/src/sys/netinet6/ip6_var.h:429:27: error: declaration of 'struct 
socket' will not be visible outside of this function [-Werror,-Wvisibility]
   429 | int     rip6_ctloutput(struct socket *, struct sockopt *);
       |                               ^
/usr/src/sys/netinet6/ip6_var.h:430:24: error: declaration of 'struct 
socket' will not be visible outside of this function [-Werror,-Wvisibility]
   430 | int     rip6_usrreq(struct socket *,
       |                            ^
5 errors generated.