Add missing includes.

Change-Id: Id6a97bfdb28f155f691891c746cbc1008e6ce083
Exempt-From-Owner-Approval: trivial cleanup
Test: mma
Bug: None
diff --git a/modules/camera/3_0/Metadata.cpp b/modules/camera/3_0/Metadata.cpp
index 440da5f..9b8eb1d 100644
--- a/modules/camera/3_0/Metadata.cpp
+++ b/modules/camera/3_0/Metadata.cpp
@@ -16,6 +16,8 @@
 //#define LOG_NDEBUG 0
 #define LOG_TAG "Metadata"
 
+#include <errno.h>
+
 #include <system/camera_metadata.h>
 
 #include <log/log.h>