util/fifo8: Introduce fifo8_drop()

Add the fifo8_drop() helper for clarity.
It is a simple wrapper over fifo8_pop_buf().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20240722160745.67904-8-philmd@linaro.org>

util/fifo8.c

@@ -131,6 +131,12 @@ uint32_t fifo8_pop_buf(Fifo8 *fifo, uint8_t *dest, uint32_t destlen)
     return n1 + n2;
 }
 
+void fifo8_drop(Fifo8 *fifo, uint32_t len)
+{
+    len -= fifo8_pop_buf(fifo, NULL, len);
+    assert(len == 0);
+}
+
 bool fifo8_is_empty(Fifo8 *fifo)
 {
     return (fifo->num == 0);