stdlib: Fix tst-makecontext2 log when swapcontext fails

The log incorrectly prints, setcontext failed.  Update this to indicate
that actually swapcontext failed.

Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

stdlib/tst-makecontext2.c

@@ -63,7 +63,7 @@ do_test (void)
       makecontext (&ucp, (void (*) (void)) cf, 2, 78, 274);
       if (swapcontext (&ucp2, &ucp) != 0)
 	{
-	  puts ("setcontext failed");
+	  puts ("swapcontext failed");
 	  return 1;
 	}