Defines FIFO_DEPTH and use it, fixing coding style.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Luc Michel <luc.michel@amd.com>
Reviewed-by: Thomas Huth <huth@tuxfamily.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250220092903.3726-8-philmd@linaro.org>
---
 hw/char/mcf_uart.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/hw/char/mcf_uart.c b/hw/char/mcf_uart.c
index 980a12fcb7d..95f269ee9b7 100644
--- a/hw/char/mcf_uart.c
+++ b/hw/char/mcf_uart.c
@@ -17,6 +17,8 @@
 #include "chardev/char-fe.h"
 #include "qom/object.h"
 
+#define FIFO_DEPTH 4
+
 struct mcf_uart_state {
     SysBusDevice parent_obj;
 
@@ -27,7 +29,7 @@ struct mcf_uart_state {
     uint8_t imr;
     uint8_t bg1;
     uint8_t bg2;
-    uint8_t fifo[4];
+    uint8_t fifo[FIFO_DEPTH];
     uint8_t tb;
     int current_mr;
     int fifo_len;
@@ -247,14 +249,16 @@ static void mcf_uart_reset(DeviceState *dev)
 static void mcf_uart_push_byte(mcf_uart_state *s, uint8_t data)
 {
     /* Break events overwrite the last byte if the fifo is full.  */
-    if (s->fifo_len == 4)
+    if (s->fifo_len == FIFO_DEPTH) {
         s->fifo_len--;
+    }
 
     s->fifo[s->fifo_len] = data;
     s->fifo_len++;
     s->sr |= MCF_UART_RxRDY;
-    if (s->fifo_len == 4)
+    if (s->fifo_len == FIFO_DEPTH) {
         s->sr |= MCF_UART_FFULL;
+    }
 
     mcf_uart_update(s);
 }
-- 
2.47.1