illumos gate

Saw these issues pop up when compiling zfs(8) on FreeBSD with clang.

- The printf warnings can be easily fixed by adding "%s" to the printf calls.

/usr/src/cddl/sbin/zfs/../../../cddl/contrib/opensolaris/cmd/zfs/zfs_main.c:5022:18: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
(void) printf(*title_ptr++);
^_~~~~~~~~~
/usr/src/cddl/sbin/zfs/../../../cddl/contrib/opensolaris/cmd/zfs/zfs_main.c:5077:20: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
(void) printf(title);
^_~~
/usr/src/cddl/sbin/zfs/../../../cddl/contrib/opensolaris/cmd/zfs/zfs_main.c:5134:17: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
(void) printf(dsname);
^_~~~

- The %c should be changed to %s as "-o" is a string literal, not a single char:

/usr/src/cddl/sbin/zfs/../../../cddl/contrib/opensolaris/cmd/zfs/zfs_main.c:5885:7: warning: format specifies type 'int' but the argument has type 'char *' [-Wformat]
"-o", MNT_LINE_MAX);
^~~~