ide: check only for CACHE FLUSH command support in ide_id_has_flush_cache()

All devices supporting CACHE FLUSH EXT command should also support
CACHE FLUSH command so it is sufficient to check only for CACHE FLUSH
in ide_id_has_flush_cache().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

include/linux/ide.h

@@ -1453,8 +1453,8 @@ extern struct mutex ide_cfg_mtx;
 extern struct bus_type ide_bus_type;
 extern struct class *ide_port_class;
 
-/* check if CACHE FLUSH (EXT) command is supported (bits defined in ATA-6) */
-#define ide_id_has_flush_cache(id)	((id)[ATA_ID_CFS_ENABLE_2] & 0x3000)
+/* check if CACHE FLUSH command is supported (as defined in ATA-6) */
+#define ide_id_has_flush_cache(id)	((id)[ATA_ID_CFS_ENABLE_2] & 0x1000)
 
 /* some Maxtor disks have bit 13 defined incorrectly so check bit 10 too */
 #define ide_id_has_flush_cache_ext(id)	\