git: b8039bf5b329 - main - Fix MINIMAL build

The branch main has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=b8039bf5b329849ae1ad2ad32f5e847437d41edd

commit b8039bf5b329849ae1ad2ad32f5e847437d41edd
Author:     Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2023-07-13 18:30:01 +0000
Commit:     Kristof Provost <kp@FreeBSD.org>
CommitDate: 2023-07-14 07:18:43 +0000

    Fix MINIMAL build
    
    Pre-declare struct ucred, to fix build issues on the MINIMAL config:
    
    In file included from /usr/src/sys/netpfil/pf/pfsync_nv.c:40:
    /usr/src/sys/netinet6/ip6_var.h:384:31: error: declaration of 'struct ucred' will not be visible outside of this function [-Werror,-Wvisibility]
            struct ip6_pktopts *, struct ucred *, int);
                                         ^
    /usr/src/sys/netinet6/ip6_var.h:408:28: error: declaration of 'struct ucred' will not be visible outside of this function [-Werror,-Wvisibility]
        struct inpcb *, struct ucred *, int, struct in6_addr *, int *);
                               ^
    2 errors generated.
---
 sys/netinet6/ip6_var.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sys/netinet6/ip6_var.h b/sys/netinet6/ip6_var.h
index bc409780feec..e538afd93994 100644
--- a/sys/netinet6/ip6_var.h
+++ b/sys/netinet6/ip6_var.h
@@ -346,6 +346,7 @@ extern struct	pr_usrreqs rip6_usrreqs;
 struct sockopt;
 
 struct inpcb;
+struct ucred;
 
 int	icmp6_ctloutput(struct socket *, struct sockopt *sopt);