loongson: fix cut-and-paste mis-merge

Ingo points out that I screwed up when merging the 'timers-for-linus'
branch in commit a03fdb76

.

A bit too much copy-and-pasting caused the end result to have an
extraneous 'return' in the middle of an expression.  That was obviously
bogus.  Blush.

Reported-by-with-patch: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>