device: fix alignment of peer stats member

This was shifted by 2 bytes when making persistent keepalive into a u32.
Fix it by placing it after the aligned region.

Fixes: e739ff7 ("device: fix persistent_keepalive_interval data races")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

device/peer.go

@@ -28,7 +28,6 @@ type Peer struct {
 	device                      *Device
 	endpoint                    conn.Endpoint
 	persistentKeepaliveInterval uint32 // accessed atomically
-	disableRoaming              bool
 
 	// These fields are accessed with atomic operations, which must be
 	// 64-bit aligned even on 32-bit platforms. Go guarantees that an
@@ -41,6 +40,8 @@ type Peer struct {
 		lastHandshakeNano int64  // nano seconds since epoch
 	}
 
+	disableRoaming bool
+
 	timers struct {
 		retransmitHandshake     *Timer
 		sendKeepalive           *Timer