f2fs: Show casefolding support only when supported

The casefolding feature is only supported when CONFIG_UNICODE is set.
This modifies the feature list f2fs presents under sysfs accordingly.

Fixes: 5aba5430 ("f2fs: include charset encoding information in the superblock")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/sysfs.c

@@ -725,7 +725,9 @@ F2FS_FEATURE_RO_ATTR(lost_found, FEAT_LOST_FOUND);
 F2FS_FEATURE_RO_ATTR(verity, FEAT_VERITY);
 #endif
 F2FS_FEATURE_RO_ATTR(sb_checksum, FEAT_SB_CHECKSUM);
+#ifdef CONFIG_UNICODE
 F2FS_FEATURE_RO_ATTR(casefold, FEAT_CASEFOLD);
+#endif
 F2FS_FEATURE_RO_ATTR(readonly, FEAT_RO);
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 F2FS_FEATURE_RO_ATTR(compression, FEAT_COMPRESSION);
@@ -836,7 +838,9 @@ static struct attribute *f2fs_feat_attrs[] = {
 	ATTR_LIST(verity),
 #endif
 	ATTR_LIST(sb_checksum),
+#ifdef CONFIG_UNICODE
 	ATTR_LIST(casefold),
+#endif
 	ATTR_LIST(readonly),
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 	ATTR_LIST(compression),