Typecast to llvm::raw_fd_ostream*

Change-Id: I1ec33d9bf73168a8990881d3c81a25d5cec2ba57
diff --git a/lib/bcc/CodeEmitter.cpp b/lib/bcc/CodeEmitter.cpp
index 38fc281..cb10b55 100644
--- a/lib/bcc/CodeEmitter.cpp
+++ b/lib/bcc/CodeEmitter.cpp
@@ -1228,7 +1228,7 @@
 
 #if defined(USE_DISASSEMBLER_FILE)
   // If you want the disassemble results write to file, uncomment this.
-  OS->close();
+  ((llvm::raw_fd_ostream*)OS)->close();
   delete OS;
 #endif