journal: remove using octal constant as the journal file permission

Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
util: add BUILD_BUG_ON() for detecting errors at compile time

This patch adds BUILD_BUG_ON() to include/util.h. The macro can be
used for detecting errors which should cause build
error. e.g. checking struct sizes, etc.

Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
journal: use BUILD_BUG_ON() for checking the size of struct journal_descriptor

This patch adds BUILD_BUG_ON() for checking the size of struct
journal_descriptor. Even if the struct modified in wrong manners, the
BUILD_BUG_ON() can detect the invalid changes (on the size).

Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>