--scan shouldn't return ses devices on FreeBSD

[asomers]

On FreeBSD, SCSI Enclosure Services devices show up as /dev/sesX. These devices don't support SMART, or any related SCSI log pages, so they ought to be suppressed from the output of smartctl --scan.

Here's an example output of smartctl -a /dev/ses0. Not much to see here:

$ sudo smartctl -a /dev/ses0
smartctl 7.0 2018-12-30 r4883 [FreeBSD 12.1-STABLE amd64] (local build)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Vendor:               NEWISYS
Product:              NDS-4600-JD
Revision:             0509
Compliance:           SPC-3
Logical Unit id:      0x500093d001896000
Serial number:        MXE3400043PRB07A
Device type:          enclosure
Transport protocol:   SAS (SPL-3)
Local Time is:        Thu Feb 13 02:50:39 2020 UTC
SMART support is:     Unavailable - device lacks SMART capability.

=== START OF READ SMART DATA SECTION ===
Current Drive Temperature:     0 C
Drive Trip Temperature:        0 C

Error Counter logging not supported

Device does not support Self Test logging


$ smartctl --version
smartctl 7.0 2018-12-30 r4883 [FreeBSD 12.1-STABLE amd64] (local build)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org

smartctl comes with ABSOLUTELY NO WARRANTY. This is free
software, and you are welcome to redistribute it under
the terms of the GNU General Public License; either
version 2, or (at your option) any later version.
See http://www.gnu.org for further details.

smartmontools release 7.0 dated 2018-12-30 at 14:47:55 UTC
smartmontools SVN rev 4883 dated 2018-12-30 at 14:48:54
smartmontools build host: amd64-portbld-freebsd12.1
smartmontools build with: C++14, GCC 4.2.1 Compatible FreeBSD Clang 8.0.1 (tags/RELEASE_801/final 366581)
smartmontools configure arguments: '--disable-dependency-tracking' '--enable-sample' '--with-nvme-devicescan=yes' '--with-initscriptdir=/usr/local/etc/rc.d' '--prefix=/usr/local' '--localstatedir=/var' '--mandir=/usr/local/man' '--disable-silent-rules' '--infodir=/usr/local/share/info/' '--build=amd64-portbld-freebsd12.1' 'build_alias=amd64-portbld-freebsd12.1' 'CXX=c++' 'CXXFLAGS=-O2 -pipe -fstack-protector-strong -fno-strict-aliasing  ' 'LDFLAGS= -fstack-protector-strong ' 'LIBS=' 'CPPFLAGS=' 'CC=cc' 'CFLAGS=-O2 -pipe  -fstack-protector-strong -fno-strict-aliasing '