ErasureCodeLrc.h: fix data_chunk_count UNINIT_CTOR

CID 1238903 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
 uninit_member: Non-static class member data_chunk_count is not
 initialized in this constructor nor in any functions that it calls.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>