A fix and a helper macro for the thread library.

The fix solves the problem of giving the last slice from a pool.

The helper macro makes utcb space creation easy for the user because we have to
consider a few things like alignment and total allocated space.

conts/libl4thread/include/l4thread/thread.h

@@ -6,6 +6,10 @@
 #ifndef __LIB_THREAD_H__
 #define __LIB_THREAD_H__
 
+/* A helper macro easing utcb space creation. */
+#define DECLARE_UTCB_SPACE(name, entries) \
+	char name[(entries + PAGE_SIZE / UTCB_SIZE) * UTCB_SIZE] ALIGN(PAGE_SIZE);
+
 int l4_set_stack_params(unsigned long stack_top,
 			unsigned long stack_bottom,
 			unsigned long stack_size);