xen/mce: fix up xen_late_init_mcelog() error handling

Static checkers complain about the missing call to misc_deregister() if
bind_virq_for_mce() fails.

Also I reversed the tests so that we do error handling instead of
success handling.  That way we just have a series of function calls
instead of the more complicated nested if statements in the original
code.  Let's preserve the error codes as well.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

1 files changed, 18 insertions, 7 deletions

diff --git a/drivers/xen/mcelog.c b/drivers/xen/mcelog.c
index 6ab6a79c38a5..a493c7315e94 100644
--- a/drivers/xen/mcelog.c
+++ b/drivers/xen/mcelog.c
@@ -393,14 +393,25 @@ static int bind_virq_for_mce(void)
 
 static int __init xen_late_init_mcelog(void)
 {
+        int ret;
+
         /* Only DOM0 is responsible for MCE logging */
-        if (xen_initial_domain()) {
-                /* register character device /dev/mcelog for xen mcelog */
-                if (misc_register(&xen_mce_chrdev_device))
-                        return -ENODEV;
-                return bind_virq_for_mce();
-        }
+        if (!xen_initial_domain())
+                return -ENODEV;
+
+        /* register character device /dev/mcelog for xen mcelog */
+        ret = misc_register(&xen_mce_chrdev_device);
+        if (ret)
+                return ret;
+
+        ret = bind_virq_for_mce();
+        if (ret)
+                goto deregister;
 
-        return -ENODEV;
+        return 0;
+
+deregister:
+        misc_deregister(&xen_mce_chrdev_device);
+        return ret;
 }
 device_initcall(xen_late_init_mcelog);