fix(internal-msg): correctly handle error (#627)

* fix(internal-msg): correctly handle error

- fixes #621

Author: frrist

lens/lily/impl.go

@@ -164,7 +164,7 @@ func (m *LilyNodeAPI) GetMessageExecutionsForTipSet(ctx context.Context, ts *typ
 
 	// if lily was watching the chain when this tipset was applied then its exec monitor will already
 	// contain executions for this tipset.
-	executions, err := msgMonitor.ExecutionFor(pts) //lint:ignore SA4006 false positive
+	executions, err := msgMonitor.ExecutionFor(pts)
 	if err == modules.ExecutionTraceNotFound {
 		// if lily hasn't watched this tipset be applied then we need to compute its execution trace.
 		// this will likely be the case for most walk tasks.
@@ -177,7 +177,8 @@ func (m *LilyNodeAPI) GetMessageExecutionsForTipSet(ctx context.Context, ts *typ
 		if err != nil {
 			return nil, xerrors.Errorf("failed to find execution trace for tipset: %s", pts.Key().String())
 		}
-	} else {
+	}
+	if err != nil {
 		return nil, xerrors.Errorf("failed to extract message execution for tipset %s: %w", ts, err)
 	}