<hardware/qemu_pipe.h>: Allow inclusion from C++

Change-Id: Ic33b5daf7a01e8fe638ea1ccc54ed76561745abe
diff --git a/include/hardware/qemu_pipe.h b/include/hardware/qemu_pipe.h
index 146fea7..fb0bf2f 100644
--- a/include/hardware/qemu_pipe.h
+++ b/include/hardware/qemu_pipe.h
@@ -16,6 +16,10 @@
 #ifndef ANDROID_INCLUDE_HARDWARE_QEMU_PIPE_H
 #define ANDROID_INCLUDE_HARDWARE_QEMU_PIPE_H
 
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
 /* Try to open a new Qemu fast-pipe. This function returns a file descriptor
  * that can be used to communicate with a named service managed by the
  * emulator.
@@ -40,4 +44,6 @@
  */
 extern int  qemu_pipe_open(const char*  pipeName);
 
+__END_DECLS
+
 #endif /* ANDROID_INCLUDE_HARDWARE_QEMUD_PIPE_H */