Currently i_blkbits is always set to SPA_MINBLOCKSHIFT every time
zfs_inode_update_impl is called. Since this value never changes
move its assignment to at inode creation time.
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4906