Fix the following -Werror warning from clang 10.0.0 in bsnmpd:

usr.sbin/bsnmpd/modules/snmp_pf/pf_snmp.c:1661:4: error: misleading indentation; statement is not part of the previous 'else' [-Werror,-Wmisleading-indentation]
                        return (-1);
                        ^
usr.sbin/bsnmpd/modules/snmp_pf/pf_snmp.c:1658:5: note: previous statement is here
                } else
                  ^

The intent was to group the return statement with the previous syslog()
call.

MFC after:	3 days

usr.sbin/bsnmpd/modules/snmp_pf/pf_snmp.c

@@ -1655,10 +1655,11 @@ altq_is_enabled(int pfdev)
 			syslog(LOG_INFO, "No ALTQ support in kernel\n"
 			    "ALTQ related functions disabled\n");
 			return (0);
-		} else
+		} else {
 			syslog(LOG_ERR, "DIOCGETALTQS returned an error: %s",
 			    strerror(errno));
 			return (-1);
+		}
 	}
 	return (1);
 }