fix missing closing bracket for extern "C" statement in tinymp3.h

Bug: 18100030.
Change-Id: I268aef41dabbafdcaef7c926636bf7bfe7089b1b
diff --git a/include/tinycompress/tinymp3.h b/include/tinycompress/tinymp3.h
index b7b45e3..aa5aca3 100644
--- a/include/tinycompress/tinymp3.h
+++ b/include/tinycompress/tinymp3.h
@@ -103,4 +103,8 @@
 	MONO = 0x03
 };
 
+#if defined(__cplusplus)
+}
+#endif
+
 #endif