Fix warning reported by Clang static code analyzer:
    CC      tools/virtiofsd/passthrough_ll.o
  tools/virtiofsd/passthrough_ll.c:1083:5: warning: Value stored to 'saverr' is never read
      saverr = ENOMEM;
      ^        ~~~~~~
Fixes: 7c6b66027
Reported-by: Clang Static Analyzer
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
         return;
     }
 
-    saverr = ENOMEM;
-
     saverr = lo_change_cred(req, &old);
     if (saverr) {
         goto out;