osd/OSD.cc: parse lsb release data via lsb_release

Use lsb_release tool to be portable since parsing /etc/lsb-release
is not the same between different distributions. The old code failed
e.g. for SUSE products to parse LSB information.

Fixes: #8654

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
(cherry picked from commit 0b3a3987d382ff33fdf892f189b30df22be80e59)
osdmaptool/test-map-pgs.t: fix escaping to fix run

Run failed always running into the '|| cat $OUT' case due
to bad escaping of '\t'. This is caused by different shells
on different distros (e.g. bash on SUSE vs dash on Ubuntu).

Use 'grep -P ' and fix the regex to make it shell independet.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
(cherry picked from commit be70c1ffe36cea56e3213bd71a47c27d7fa2a068)
test/ceph-disk.sh: fix for SUSE

On SUSE 'which' returns always the full path of (shell) commands and
not e.g. './ceph-conf' as on Debian. Add check also for full
path returned by which.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
(cherry picked from commit 39530536ff923b91899f6303507c283b78040a20)