x86: check function status in EDD boot code

Without checking the return value of get_edd_info() and adding the
entry only in the success case, 6 devices show up under
/sys/firmware/edd/, no matter how many devices are actually present.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

arch/x86/boot/edd.c

@@ -167,9 +167,8 @@ void query_edd(void)
 		 * Scan the BIOS-supported hard disks and query EDD
 		 * information...
 		 */
-		get_edd_info(devno, &ei);
-
-		if (boot_params.eddbuf_entries < EDDMAXNR) {
+		if (!get_edd_info(devno, &ei)
+		    && boot_params.eddbuf_entries < EDDMAXNR) {
 			memcpy(edp, &ei, sizeof ei);
 			edp++;
 			boot_params.eddbuf_entries++;