pfctl: fix man page and error message for -S option

The `pfctl -S` flag was added to disable DNS resolution in
<https://reviews.freebsd.org/D50724> but documentation and error
messages refer to a `pfctl -N` flag for the same purpose. The `pfctl -N`
flag performs an unrelated function, so the docs and error messages need
to be changed. Caught this when revising documentation for the `-N`
flag.

Reviewed by:	kp
Signed-off-by:	Ross Williams <ross@ross-williams.net>

sbin/pfctl/pfctl.8

@@ -24,7 +24,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd December 30, 2025
+.Dd April 20, 2026
 .Dt PFCTL 8
 .Os
 .Sh NAME
@@ -458,7 +458,7 @@ and
 flags to load multiple rule types without (re)loading all rules.
 .It Fl r
 Perform reverse DNS lookups on states and tables when displaying them.
-.Fl N
+.Fl S
 and
 .Fl r
 are mutually exclusive.

sbin/pfctl/pfctl.c

@@ -3809,7 +3809,7 @@ main(int argc, char *argv[])
 	}
 
 	if ((opts & PF_OPT_NODNS) && (opts & PF_OPT_USEDNS))
-		errx(1, "-N and -r are mutually exclusive");
+		errx(1, "-S and -r are mutually exclusive");
 
 	if ((tblcmdopt == NULL) ^ (tableopt == NULL) &&
 	    (tblcmdopt == NULL || *tblcmdopt != 'l'))