i3c: phytium: initialize variable 'ret' when !master->prescl0

Fix follow error with clang-19:

drivers/i3c/master/i3c-master-phytium.c:1710:7: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
 1710 |                 if (!master->prescl0)
      |                     ^~~~~~~~~~~~~~~~
drivers/i3c/master/i3c-master-phytium.c:1788:9: note: uninitialized use occurs here
 1788 |         return ret;
      |                ^~~
drivers/i3c/master/i3c-master-phytium.c:1710:3: note: remove the 'if' if its condition is always false
 1710 |                 if (!master->prescl0)
      |                 ^~~~~~~~~~~~~~~~~~~~~
 1711 |                         goto err_disable_sysclk;
      |                         ~~~~~~~~~~~~~~~~~~~~~~~
drivers/i3c/master/i3c-master-phytium.c:1669:9: note: initialize the variable 'ret' to silence this warning
 1669 |         int ret, irq;
      |                ^
      |                 = 0
1 error generated.

Signed-off-by: WangYuli <[email protected]>

drivers/i3c/master/i3c-master-phytium.c

@@ -1666,7 +1666,8 @@ static int phytium_i3c_master_probe(struct platform_device *pdev)
 {
 	struct phytium_i3c_master *master;
 	struct resource *res;
-	int ret, irq;
+	int ret = -EINVAL;
+	int irq;
 	u32 val;
 
 	master = devm_kzalloc(&pdev->dev, sizeof(*master), GFP_KERNEL);