lint: add errchecks (#5316)

## Description

Work towards enabling errcheck

ref #5059

rpc/jsonrpc/client/ws_client.go

@@ -349,7 +349,10 @@ func (c *WSClient) reconnectRoutine() {
 			c.wg.Wait()
 			if err := c.reconnect(); err != nil {
 				c.Logger.Error("failed to reconnect", "err", err, "original_err", originalError)
-				c.Stop()
+				if err = c.Stop(); err != nil {
+					c.Logger.Error("failed to stop conn", "error", err)
+				}
+
 				return
 			}
 			// drain reconnectAfter

rpc/jsonrpc/server/ws_handler.go

@@ -99,7 +99,9 @@ func (wm *WebsocketManager) WebsocketHandler(w http.ResponseWriter, r *http.Requ
 		wm.logger.Error("Failed to start connection", "err", err)
 		return
 	}
-	con.Stop()
+	if err := con.Stop(); err != nil {
+		wm.logger.Error("error while stopping connection", "error", err)
+	}
 }
 
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