erofs: get rid of ROOT_NID()

Let's open code this helper for simplicity.
Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20231026021627.23284-1-mengferry@linux.alibaba.comSigned-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

fs/erofs/internal.h

@@ -228,8 +228,6 @@ struct erofs_buf {
 };
 #define __EROFS_BUF_INITIALIZER	((struct erofs_buf){ .page = NULL })
 
-#define ROOT_NID(sb)		((sb)->root_nid)
-
 #define erofs_blknr(sb, addr)	((addr) >> (sb)->s_blocksize_bits)
 #define erofs_blkoff(sb, addr)	((addr) & ((sb)->s_blocksize - 1))
 #define erofs_pos(sb, blk)	((erofs_off_t)(blk) << (sb)->s_blocksize_bits)

fs/erofs/super.c

@@ -668,13 +668,13 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
 	xa_init(&sbi->managed_pslots);
 #endif
 
-	inode = erofs_iget(sb, ROOT_NID(sbi));
+	inode = erofs_iget(sb, sbi->root_nid);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
 	if (!S_ISDIR(inode->i_mode)) {
 		erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)",
-			  ROOT_NID(sbi), inode->i_mode);
+			  sbi->root_nid, inode->i_mode);
 		iput(inode);
 		return -EINVAL;
 	}
@@ -704,7 +704,7 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
 	if (err)
 		return err;
 
-	erofs_info(sb, "mounted with root inode @ nid %llu.", ROOT_NID(sbi));
+	erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid);
 	return 0;
 }