fix some issues with supername code

1. Apparently on builds using FORTIFY_SOURCE the game would SIGABRT on the line strcpy(someone, skin->realname); despite both someone and realname buffers being SKINNAMESIZE+1 sized. I replaced it with one string the same size as supername and used strlcat instead so that should hopefully no longer happen.

2. There was a misplaced else that could cause supername to never have the skin name copied over it if hudname and realname were both not supplied. Wouldn't crash but would display the failsafe "someone super" instead. Now it should display the skin name as intended.