Address review comment.

Author: bzbarsky-apple

src/darwin/Framework/CHIPTests/MTRCertificateValidityTests.m

@@ -163,7 +163,7 @@ - (void)issueOperationalCertificateForRequest:(MTROperationalCSRInfo *)csrInfo
 
     __auto_type * operationalCertificate = [self issueOperationalCertificateForNode:@(kDeviceId)
                                                                operationalPublicKey:operationalPublicKey];
-    // Release no-longer-needed key key before we do anything else.
+    // Release no-longer-needed key before we do anything else.
     CFRelease(operationalPublicKey);
     XCTAssertNotNil(operationalCertificate);
 

src/darwin/Framework/CHIPTests/MTRPerControllerStorageTests.m

@@ -158,7 +158,7 @@ - (void)issueOperationalCertificateForRequest:(MTROperationalCSRInfo *)csrInfo
                                                                            nodeID:self.nextNodeID
                                                             caseAuthenticatedTags:nil
                                                                             error:&error];
-    // Release no-longer-needed key key before we do anything else.
+    // Release no-longer-needed key before we do anything else.
     CFRelease(publicKey);
     XCTAssertNil(error);
     XCTAssertNotNil(operationalCert);