perf(p2p): Remove unnecessary atomic read (backport cometbft#2950) (c…

…ometbft#2972) (#41)

This PR is a driveby change. We were doing an atomic read here, but this
is unnecessary. Nothing in the codebase modified this variable after
instantiation.

Doesn't really feel changelog worthy, but I can add one if we want. Felt
like a minor code nit<hr>This is an automatic backport of pull request
cometbft#2950 done by [Mergify](https://mergify.com).

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: Dev Ojha <ValarDragon@users.noreply.github.com>
(cherry picked from commit c1cebed)

p2p/conn/connection.go

@@ -505,7 +505,7 @@ func (c *MConnection) sendSomePacketMsgs() bool {
 	// Block until .sendMonitor says we can write.
 	// Once we're ready we send more than we asked for,
 	// but amortized it should even out.
-	c.sendMonitor.Limit(c._maxPacketMsgSize, atomic.LoadInt64(&c.config.SendRate), true)
+	c.sendMonitor.Limit(c._maxPacketMsgSize, c.config.SendRate, true)
 
 	// Now send some PacketMsgs.
 	for i := 0; i < numBatchPacketMsgs; i++ {