FreeBSD prefixes libssh symbols with "Fssh_" in ssh_namespace.h. Thissshkey.c references sshsk_sign(), which is defined in ${SKSRCS}.
Due to how FreeBSD builds libssh, we need to partially revert
header file is included in all targets that consume libssh (in65d8491719bb ("secure: Adapt Makefile to ssh-sk-client everywhere") and
secure/ssh.mk). It needs access to all the definition implementations,add ${SKSRCS} back to avoid linking problems, especially when building
some of them are in ${SKSRCS}with GCC.
Note that this is a FreeBSD-specific requirementPut the sources in a separate line, that is why we put itto maintain line-by-line
in a separate sources line.compatibility with upstream Makefile.in
PR: 286580
Fixes: 65d8491719bb ("secure: Adapt Makefile to ssh-sk-client everywhere")