No need to include pthread.h inside bitmap_malloc()

src/bitmap/bitmap_malloc.c

@@ -28,10 +28,6 @@
 
 #include "trace.h"
 
-#ifdef HAVE_LOCKS
-#include <pthread.h>
-#endif /* HAVE_LOCKS */
-
 #ifdef WITH_ALLOCATOR_STATS
 #include "dmmlib/dmmlib.h"
 #endif /* WITH_ALLOCATOR_STATS */