fix(typos): fix typos for lv_draw_buf (#4492)

Signed-off-by: XiaoweiYan <yanxiaowei@xiaomi.com>
Co-authored-by: XiaoweiYan <yanxiaowei@xiaomi.com>

src/draw/lv_draw_buf.c

@@ -1,5 +1,5 @@
 /**
- * @file lv_draw_buf_basic.c
+ * @file lv_draw_buf.c
  *
  */
 
@@ -66,7 +66,7 @@ void _lv_draw_buf_init_handlers(void)
     handlers.buf_copy_cb = buf_copy;
 }
 
-lv_draw_buf_handlers_t * lv_draw_bug_get_handlers(void)
+lv_draw_buf_handlers_t * lv_draw_buf_get_handlers(void)
 {
     return &handlers;
 }

src/draw/lv_draw_buf.h

@@ -86,7 +86,7 @@ void _lv_draw_buf_init_handlers(void);
  * Custom callback can be set on the returned value
  * @return                  pointer to the struct of handlers
  */
-lv_draw_buf_handlers_t * lv_draw_bug_get_handlers(void);
+lv_draw_buf_handlers_t * lv_draw_buf_get_handlers(void);
 
 /**
  * Initialize a draw buffer object. The buffer won't be allocated