firmware: arm_scmi: Avoid non-constant printk format strings

A recent rework changed the constant format strings to a local variable,
which causes warnings from clang when -Wformat-security is enabled:

drivers/firmware/arm_scmi/driver.c: In function 'scmi_probe':
drivers/firmware/arm_scmi/driver.c:2936:25: error: format not a string literal and no format arguments [-Werror=format-security]
 2936 |                         dev_err(dev, err_str);
      |                         ^~~~~~~
drivers/firmware/arm_scmi/driver.c:2993:9: error: format not a string literal and no format arguments [-Werror=format-security]
 2993 |         return dev_err_probe(dev, ret, err_str);

Print these using an explicit "%s" string instead.

Fixes: 3a7d93d ("firmware: arm_scmi: Use dev_err_probe to bail out")
Signed-off-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sudeep Holla <[email protected]>

Author: arndb

drivers/firmware/arm_scmi/driver.c

@@ -2933,7 +2933,7 @@ static int scmi_probe(struct platform_device *pdev)
 	if (ret) {
 		err_str = "unable to communicate with SCMI\n";
 		if (coex) {
-			dev_err(dev, err_str);
+			dev_err(dev, "%s", err_str);
 			return 0;
 		}
 		goto notification_exit;
@@ -2990,7 +2990,7 @@ static int scmi_probe(struct platform_device *pdev)
 clear_ida:
 	ida_free(&scmi_id, info->id);
 
-	return dev_err_probe(dev, ret, err_str);
+	return dev_err_probe(dev, ret, "%s", err_str);
 }
 
 static void scmi_remove(struct platform_device *pdev)