nilfs2: fix various typos in comments

This fixes various typos I found in comments of nilfs2.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/segment.h b/fs/nilfs2/segment.h
index 3155e0c..2a79456 100644
--- a/fs/nilfs2/segment.h
+++ b/fs/nilfs2/segment.h
@@ -30,7 +30,7 @@
 #include "sb.h"
 
 /**
- * struct nilfs_recovery_info - Recovery infomation
+ * struct nilfs_recovery_info - Recovery information
  * @ri_need_recovery: Recovery status
  * @ri_super_root: Block number of the last super root
  * @ri_ri_cno: Number of the last checkpoint