Fix transitions for image_download and activation

Change-Id: I713ada52eef9d275c7d7596026e178c7382e8335
diff --git a/vendor/golang.org/x/sys/unix/syscall_linux_gc_arm.go b/vendor/golang.org/x/sys/unix/syscall_linux_gc_arm.go
new file mode 100644
index 0000000..8c514c9
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/syscall_linux_gc_arm.go
@@ -0,0 +1,13 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm,!gccgo,linux
+
+package unix
+
+import "syscall"
+
+// Underlying system call writes to newoffset via pointer.
+// Implemented in assembly to avoid allocation.
+func seek(fd int, offset int64, whence int) (newoffset int64, err syscall.Errno)