fix: remove unnecessary err check in gentx (cosmos#11883)

err is always nil, because txFactor doesn't
produce new errors

## Description
err is always nil, because txFactor doesn't
produce new errors

Closes: N/A



---

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x/genutil/client/cli/gentx.go

@@ -130,9 +130,7 @@ $ %s gentx my-key-name 1000000stake --home=/path/to/home/dir --keyring-backend=o
 			}
 
 			txFactory := tx.NewFactoryCLI(clientCtx, cmd.Flags())
-			if err != nil {
-				return errors.Wrap(err, "error creating tx builder")
-			}
+
 			pub, err := key.GetAddress()
 			if err != nil {
 				return err