nilfs2: align block comments of nilfs_sufile_truncate_range() at *

Fix the following checkpatch warning:

 WARNING: Block comments should align the * on each line
 #633: FILE: sufile.c:633:
 +/**
 +  * nilfs_sufile_truncate_range - truncate range of segment array

Link: http://lkml.kernel.org/r/1509367935-3086-4-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>