nilfs2: hide nilfs_mdt_clear calls in nilfs_mdt_destroy

This will hide a function call of nilfs_mdt_clear() in
nilfs_mdt_destroy().

This ensures nilfs_mdt_destroy() to do cleanup jobs included in
nilfs_mdt_clear().

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

diff --cc fs/nilfs2/gcinode.c
Simple merge

diff --cc fs/nilfs2/mdt.c
Simple merge

diff --cc fs/nilfs2/mdt.h
Simple merge

diff --cc fs/nilfs2/recovery.c
Simple merge

diff --cc fs/nilfs2/super.c
Simple merge

diff --cc fs/nilfs2/the_nilfs.c
Simple merge