[PATCH] pfinet: fix privilege check in S_iioctl_siocsifmtu

Non-root users could bypass the EPERM check and still modify
the interface MTU because the isroot check was not chained into
the same if-else block as the device and mtu validation.

Add the missing else to ensure the modification is skipped when
the caller is not root.
---
 pfinet/iioctl-ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pfinet/iioctl-ops.c b/pfinet/iioctl-ops.c
index aae09df1..ccebec87 100644
--- a/pfinet/iioctl-ops.c
+++ b/pfinet/iioctl-ops.c
@@ -596,7 +596,7 @@ S_iioctl_siocsifmtu (struct sock_user *user,
 
   if (!user->isroot)
     err = EPERM;
-  if (!dev)
+  else if (!dev)
     err = ENODEV;
   else if (mtu <= 0)
     err = EINVAL;
-- 
2.54.0