ext4: Don't ask about supporting ext2/3 in ext4 if ext4 is not configured

Don't offer to build ext2/3 support into ext4 if ext4 itself is not
configured on.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index 9acf7e8..9ed1bb1 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -28,6 +28,7 @@
 
 config EXT4_USE_FOR_EXT23
 	bool "Use ext4 for ext2/ext3 file systems"
+	depends on EXT4_FS
 	depends on EXT3_FS=n || EXT2_FS=n
 	default y
 	help