[DF][NFC] Compare to static TClassRef instead of string
[DF][NFC] Compare to static TClassRef instead of string

It's slightly faster when the comparison is expected to be performed many times.

Co-authored-by: Philippe Canal <69612018eea270a331b01ca4491eb7b1b815033a@fnal.gov>
olifre/root,root-mirror/root,olifre/root,karies/root,karies/root,karies/root,karies/root,karies/root,root-mirror/root,root-mirror/root,karies/root,karies/root,olifre/root,karies/root,olifre/root,olifre/root,olifre/root,olifre/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,karies/root