fix golangcli-lint complaint (#2463) (#2477)

## Description

closes: #XXXX

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

- [x] Targeted PR against correct branch (see [CONTRIBUTING.md](https://github.com/cosmos/ibc-go/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
- [ ] Code follows the [module structure standards](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules/structure.md).
- [ ] Wrote unit and integration [tests](https://github.com/cosmos/ibc-go/blob/master/CONTRIBUTING.md#testing)
- [ ] Updated relevant documentation (`docs/`) or specification (`x/<module>/spec/`)
- [ ] Added relevant `godoc` [comments](https://blog.golang.org/godoc-documenting-go-code).
- [ ] Added a relevant changelog entry to the `Unreleased` section in `CHANGELOG.md`
- [x] Re-reviewed `Files changed` in the Github PR explorer
- [ ] Review `Codecov Report` in the comment section below once CI passes

(cherry picked from commit 503b9eb)

Co-authored-by: Carlos Rodriguez <[email protected]>
Co-authored-by: Damian Nolan <[email protected]>

modules/core/23-commitment/types/merkle.go

@@ -271,8 +271,10 @@ func verifyChainedMembershipProof(root []byte, specs []*ics23.ProofSpec, proofs
 
 // blankMerkleProof and blankProofOps will be used to compare against their zero values,
 // and are declared as globals to avoid having to unnecessarily re-allocate on every comparison.
-var blankMerkleProof = &MerkleProof{}
-var blankProofOps = &tmcrypto.ProofOps{}
+var (
+	blankMerkleProof = &MerkleProof{}
+	blankProofOps    = &tmcrypto.ProofOps{}
+)
 
 // Empty returns true if the root is empty
 func (proof *MerkleProof) Empty() bool {