Revert "add changed files"

This reverts commit c37263f594.

common/Makefile.am

@@ -31,8 +31,6 @@ endif
 endif
 
 libcommon_la_SOURCES += \
-	thread_abstraction.cpp \
-	mutex_abstraction.cpp \
 	lt_debug.cpp \
 	proc_tools.c \
 	pwrmngr.cpp

common/thread_abstraction.cpp

@@ -30,5 +30,4 @@ void Thread::joinThread()
 void* Thread::runThread(void* ptr)
 {
 	((Thread*)ptr)->run();
-	return 0;
 }