Fix the build. imgdiff.c needed #include <sys/types.h>.

Change-Id: I82169a926e7df2aa92bac2c4f427bc64f4811362
diff --git a/tools/applypatch/imgdiff.c b/tools/applypatch/imgdiff.c
index 38e3c83..6ff9b6f 100644
--- a/tools/applypatch/imgdiff.c
+++ b/tools/applypatch/imgdiff.c
@@ -119,6 +119,7 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <sys/types.h>
 
 #include "zlib.h"
 #include "imgdiff.h"