ide: 'secondary' field is only used by cmd646

Patchworks-ID: 35303
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/ide/pci.h b/hw/ide/pci.h
index 690d057..9377503 100644
--- a/hw/ide/pci.h
+++ b/hw/ide/pci.h
@@ -7,7 +7,7 @@
     PCIDevice dev;
     IDEBus bus[2];
     BMDMAState bmdma[2];
-    uint32_t secondary;
+    uint32_t secondary; /* used only for cmd646 */
 } PCIIDEState;
 
 void bmdma_cmd_writeb(void *opaque, uint32_t addr, uint32_t val);