[DAGCombiner] clean up foldAndOfSetCCs; NFCI

1. Fix bogus comment.
2. Early exit to reduce indent.
3. Change node pointer param to what it really is: an SDLoc.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298940 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed