Only enable BLOCK_COMPAT if COMPAT is needed

IOW, it needs to depend on both CONFIG_BLOCK and CONFIG_COMPAT.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block/Kconfig

@@ -62,10 +62,11 @@ config BLK_DEV_BSG
 	protocols (e.g. Task Management Functions and SMP in Serial
 	Attached SCSI).
 
-config BLOCK_COMPAT
-	bool
-	default y
-
 endif # BLOCK
 
+config BLOCK_COMPAT
+	bool
+	depends on BLOCK && COMPAT
+	default y
+
 source block/Kconfig.iosched