pfctl: Do not warn if there is no Ethernet anchor

Avoid emitting a warning if there is no Ethernet anchor.  If the anchor
--regardless of its type-- is nonexistent, should be caught earlier.

This can be misleading when there is a layer 3 anchor but not an
Ethernet anchor, giving the user the impression that there is no layer 3
anchor with that name.

PR:		280516
Approved by:	kp
MFC after:	2 days
Differential Revision:	https://reviews.freebsd.org/D53360

sbin/pfctl/pfctl.c

@@ -3167,10 +3167,7 @@ pfctl_show_eth_anchors(int dev, int opts, char *anchorname)
 	int ret;
 
 	if ((ret = pfctl_get_eth_rulesets_info(dev, &ri, anchorname)) != 0) {
-		if (ret == ENOENT)
-			fprintf(stderr, "Anchor '%s' not found.\n",
-			    anchorname);
-		else
+		if (ret != ENOENT)
 			errc(1, ret, "DIOCGETETHRULESETS");
 		return (-1);
 	}

tests/sys/netpfil/pf/anchor.sh

@@ -157,10 +157,10 @@ deeply_nested_body()
 
 	atf_check -s exit:0 -o \
 	    inline:"  foo\n  foo/bar\n  foo/bar/foobar\n  foo/bar/quux\n  foo/baz\n  foo/qux\n" \
-	    -e ignore jexec alcatraz pfctl -sA
+	    jexec alcatraz pfctl -sA
 
 	atf_check -s exit:0 -o inline:"  foo/bar/foobar\n  foo/bar/quux\n" \
-	    -e ignore jexec alcatraz pfctl -a foo/bar -sA
+	    jexec alcatraz pfctl -a foo/bar -sA
 }
 
 deeply_nested_cleanup()