Fix #8654 - OSD.cc: parse LSB 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>
could avoid this nesting by doing

if (_lsb_release_set(...))
  continue;
if (...)
  continue;
...
derr << "unabled output: " << buf << dendl;