exit status check and make sure loops return

the create command doesn't exit properly after a snapshot completes

cmd/filecoin-chain-archiver/cmds/create.go

@@ -368,6 +368,7 @@ var cmdCreate = &cli.Command{
 
 					logger.Debugw("lock aquired", "expiry", lock.Expiry())
 				}
+				break
 			}
 		}()
 
@@ -400,6 +401,9 @@ var cmdCreate = &cli.Command{
 					if size == 0 {
 						continue
 					}
+					if size == lastSize {
+						break
+					}
 					logger.Infow("update", "total", size, "speed", (size-lastSize)/int64(flagProgressUpdate/time.Second))
 					lastSize = size
 				case err := <-errCh:
@@ -408,21 +412,12 @@ var cmdCreate = &cli.Command{
 					}
 				}
 			}
+			return
 		}()
 
 		if flagDiscard {
 			logger.Infow("discarding output")
-			g, ctxGroup := errgroup.WithContext(ctx)
-			g.Go(func() error {
-				return runWriteCompressed(ctxGroup, rrPath+".zstd", rr)
-			})
-			if err := g.Wait(); err != nil {
-				return err
-			}
-
-			if err := <-errCh; err != nil {
-				return err
-			}
+			return runWriteCompressed(rrPath+".zstd", rr)
 		} else {
 			host := u.Hostname()
 			port := u.Port()
@@ -514,7 +509,7 @@ func compress(source io.Reader) io.Reader {
 	return r
 }
 
-func runWriteCompressed(ctx context.Context, path string, source io.Reader) error {
+func runWriteCompressed(path string, source io.Reader) error {
 	file, err := os.Create(path)
 	if err != nil {
 		return err