THRIFT-2082 Executing "gmake clean" is broken

Patch: Pavlin Radoslavov
diff --git a/compiler/cpp/Makefile.am b/compiler/cpp/Makefile.am
index a70129a..2c3e5dc 100644
--- a/compiler/cpp/Makefile.am
+++ b/compiler/cpp/Makefile.am
@@ -108,6 +108,6 @@
 
 clean-local:
 	$(RM) thriftl.cc thrifty.cc thrifty.h thrifty.hh version.h windows/version.h
-	echo '#include "thrifty.h"' > compiler/cpp/thrifty.hh
+	echo '#include "thrifty.h"' > thrifty.hh
 
 src/main.cc: version.h