ext4: Fix comment about the 64BIT feature

64BIT is part of the incompatible feature set, update the comment
accordingly.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20230301133842.671821-1-tudor.ambarus@linaro.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/ext4.h

@@ -1387,7 +1387,7 @@ struct ext4_super_block {
 	__le32	s_first_meta_bg;	/* First metablock block group */
 	__le32	s_mkfs_time;		/* When the filesystem was created */
 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
-	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
+	/* 64bit support valid if EXT4_FEATURE_INCOMPAT_64BIT */
 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
 	__le32	s_free_blocks_count_hi;	/* Free blocks count */