Add #include errno.h

Test: Local build
Change-Id: Ie588c738fe7f7fc27c1d514af2cb122c21d89eba
(cherry picked from commit d17022439ff26e77cf25da62448720fd320a3e63)
diff --git a/guest/hals/gralloc/gralloc_vsoc_priv.h b/guest/hals/gralloc/gralloc_vsoc_priv.h
index 3f4d179..1ec5659 100644
--- a/guest/hals/gralloc/gralloc_vsoc_priv.h
+++ b/guest/hals/gralloc/gralloc_vsoc_priv.h
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+#include <errno.h>
 #include <cutils/native_handle.h>
 #include <hardware/gralloc.h>
 #include <log/log.h>