[#324] rpc: Fix mem leak

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

api/rpc/client/init.go

@@ -52,6 +52,7 @@ func (c *Client) Init(info common.CallMethodInfo, opts ...CallOption) (MessageRe
 	}
 
 	ctx, cancel := context.WithCancel(prm.ctx)
+	defer cancel()
 
 	// `conn.NewStream` doesn't check if `conn` may turn up invalidated right before this invocation.
 	// In such cases, the operation can hang indefinitely, with the context timeout being the only
@@ -61,7 +62,13 @@ func (c *Client) Init(info common.CallMethodInfo, opts ...CallOption) (MessageRe
 	// would propagate to all subsequent read/write operations on the opened stream,
 	// which is not desired for the stream's lifecycle management.
 	dialTimeoutTimer := time.NewTimer(c.dialTimeout)
-	defer dialTimeoutTimer.Stop()
+	defer func() {
+		dialTimeoutTimer.Stop()
+		select {
+		case <-dialTimeoutTimer.C:
+		default:
+		}
+	}()
 
 	type newStreamRes struct {
 		stream grpc.ClientStream