cifs: fix mount option display for sec=krb5i

Fix display for sec=krb5i which was wrongly interleaved by cruid,
resulting in string "sec=krb5,cruid=<...>i" instead of
"sec=krb5i,cruid=<...>".

Fixes: 96281b9e ("smb3: for kerberos mounts display the credential uid used")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>