regulator: scmi: Use int type to store negative error codes

Change the 'ret' variable from u32 to int to store negative error codes or
zero returned by of_property_read_u32().

Storing the negative error codes in unsigned type, doesn't cause an issue
at runtime but it's ugly as pants. Additionally, assigning negative error
codes to unsigned type may trigger a GCC warning when the -Wsign-conversion
flag is enabled.

No effect on runtime.

Signed-off-by: Qianfeng Rong <[e-mail]>
Reviewed-by: Sudeep Holla <[e-mail]>
Fixes: 0fbeae70ee7c ("regulator: add SCMI driver")
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/scmi-regulator.c

···
 					  struct device_node *np,
 					  struct scmi_regulator_info *rinfo)
 {
-	u32 dom, ret;
+	u32 dom;
+	int ret;
 
 	ret = of_property_read_u32(np, "reg", &dom);
 	if (ret)