nilfs2: fix style problems in nilfs2_fs.h

This kills the following checkpatch warnings:

WARNING: please, no space before tabs
+^I__le32^Is_first_ino; ^I^I/* First non-reserved inode */$

WARNING: please, no space before tabs
+^I__le16  s_inode_size; ^I^I/* Size of an inode */$

WARNING: please, no space before tabs
+^Ichar^Is_volume_name[16]; ^I/* volume name */$

WARNING: please, no space before tabs
+^Ichar^Is_last_mounted[64]; ^I/* directory where last mounted */$
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

include/linux/nilfs2_fs.h

@@ -199,16 +199,16 @@ struct nilfs_super_block {
 	__le32	s_creator_os;		/* OS */
 	__le16	s_def_resuid;		/* Default uid for reserved blocks */
 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
-	__le32	s_first_ino; 		/* First non-reserved inode */
+	__le32	s_first_ino;		/* First non-reserved inode */
 
-	__le16  s_inode_size; 		/* Size of an inode */
+	__le16  s_inode_size;		/* Size of an inode */
 	__le16  s_dat_entry_size;       /* Size of a dat entry */
 	__le16  s_checkpoint_size;      /* Size of a checkpoint */
 	__le16	s_segment_usage_size;	/* Size of a segment usage */
 
 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
-	char	s_volume_name[16]; 	/* volume name */
-	char	s_last_mounted[64]; 	/* directory where last mounted */
+	char	s_volume_name[16];	/* volume name */
+	char	s_last_mounted[64];	/* directory where last mounted */
 
 	__le32  s_c_interval;           /* Commit interval of segment */
 	__le32  s_c_block_max;          /* Threshold of data amount for