Fix "device/asus/fugu/recovery/recovery_updater.c:181:101: error: 'errno' undeclared".

Change-Id: Ife865a7ee8909f5ad6d45d25c48f540406c0e790
diff --git a/recovery/recovery_updater.c b/recovery/recovery_updater.c
index 1c559ce..75dd635 100644
--- a/recovery/recovery_updater.c
+++ b/recovery/recovery_updater.c
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <errno.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <stdbool.h>