Fix misaligned struct member used in atomic operation

This fixes a panic caused by attempting to atomically access a struct
member which is not 64-bit aligned when running on 32-bit arch, due to
the smaller sync.Map struct.

Fixes: #2518

Signed-off-by: Daniel Swarbrick <daniel.swarbrick@gmail.com>

service/internal/endpoint-discovery/cache.go

@@ -9,12 +9,12 @@ import (
 // based on some key. The data structure makes use of a read write
 // mutex to enable asynchronous use.
 type EndpointCache struct {
-	endpoints     sync.Map
-	endpointLimit int64
 	// size is used to count the number elements in the cache.
 	// The atomic package is used to ensure this size is accurate when
 	// using multiple goroutines.
-	size int64
+	size          int64
+	endpoints     sync.Map
+	endpointLimit int64
 }
 
 // NewEndpointCache will return a newly initialized cache with a limit