nilfs2: deleted struct nilfs_dat_group_desc
nilfs2: deleted struct nilfs_dat_group_desc

struct nilfs_dat_group_desc is not used both in kernel and user spaces.
struct nilfs_palloc_group_desc is used instead.

Signed-off-by: Jiro SEKIBA <5bf4ce6b1d16b8e72b3c064fd853f5e60cd6303c@unicus.jp>
Signed-off-by: Ryusuke Konishi <f414f2bdd839fdc054376382fa67e9bc2fbf206f@lab.ntt.co.jp>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs