Update email address and CREDITS info.  xenotime.net is defunct.

Signed-off-by: Randy Dunlap <[email protected]>
Cc: Harry Wei <[email protected]>
Cc: Keiichi KII <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>