net/irda compile warnings in 2.4.21-pre3

I have fixed the compile warnings in net/irda that happened because of GCC's deprication of the concentenation of string literals with __FUNCTION__.
Tested on my tree. This my first patch, if it's not in optimal format, I apologize.

The patch is at
http://www.chainsaw.cistron.nl/compile-fixes-irda.patch.gz

It should apply cleanly to vanilla 2.4.21-pre3 sources.

Tony.