ide: Use some already defined page macros instead of constants

Some PAGE constants were used instead of the macros we already have
defined in internal.h.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

hw/ide/core.c

diff --git a/hw/ide/core.c b/hw/ide/core.c
index a5b00ae..e40fc75 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -1250,7 +1250,7 @@
             switch(action) {
             case 0: /* current values */
                 switch(code) {
-                case 0x01: /* error recovery */
+                case GPMODE_R_W_ERROR_PAGE: /* error recovery */
                     cpu_to_ube16(&buf[0], 16 + 6);
                     buf[2] = 0x70;
                     buf[3] = 0;
@@ -1269,7 +1269,7 @@
                     buf[15] = 0x00;
                     ide_atapi_cmd_reply(s, 16, max_len);
                     break;
-                case 0x2a:
+                case GPMODE_CAPABILITIES_PAGE:
                     cpu_to_ube16(&buf[0], 28 + 6);
                     buf[2] = 0x70;
                     buf[3] = 0;