kernel: printk: Add non exported function for clearing the log ring buffer

Signed-off-by: San Mehat <san@google.com>

kernel/printk.c

@@ -305,6 +305,14 @@ static int log_buf_get_len(void)
 	return logged_chars;
 }
 
+/*
+ * Clears the ring-buffer
+ */
+void log_buf_clear(void)
+{
+	logged_chars = 0;
+}
+
 /*
  * Copy a range of characters from the log buffer.
  */