删除rt_thread_sleep遗留

examples/libc/ex6.c

@@ -12,7 +12,7 @@
 #include <pthread.h>
 #include <unistd.h>
 
-#define usleep rt_thread_sleep
+#define usleep rt_thread_delay
 
 static void *test_thread(void *v_param) {
     return NULL;

examples/libc/ex7.c

@@ -18,7 +18,7 @@
 #include <sys/time.h>
 #include <unistd.h>
 
-#define usleep rt_thread_sleep
+#define usleep rt_thread_delay
 
 /* Our event variable using a condition variable contruct. */
 typedef struct {

examples/libc/file.c

@@ -57,7 +57,7 @@ FINSH_FUNCTION_EXPORT(libc_lseek, lseek test for libc);
 
 void sleep(int tick)
 {
-    rt_thread_sleep(tick);
+    rt_thread_delay(tick);
 }
 
 int libc_fseek(void)