dm: Use libdevmapper instead of dmsetup to get subsystem from name#1159

vojtechtrefny merged 3 commits intostoraged-project:masterstoraged-project/libblockdev:masterfrom

vojtechtrefny:master_dm-subsystem-libdevmappervojtechtrefny/libblockdev:master_dm-subsystem-libdevmapperCopy head branch name to clipboard