Issue found by new nilness vet check

[dgryski]

Playing with the new vet, I found the following issue:

$ vet ./...
/Users/dgryski/go/src/github.com/dgraph-io/dgraph/query/query.go:544:16: impossible condition: nil != nil

The line is https://github.com/dgraph-io/dgraph/blob/master/query/query.go#L544 , and facetsNode has not been assigned a value between declaration on line 384 and the if test, so it's always nil.

[srfrog]

Hi, which new vet is this? We use the vet tool that comes with Go.

[dgryski]

It was just merged into master.

https://go-review.googlesource.com/c/go/+/149609/

[manishrjain]

Thanks for catching this, @dgryski ! Seems like a bug at our end.