syncmap: remove redundant type conversion

Change-Id: I32c367338e1ea95aaaaa8e891f5dfe4ab6c03913
GitHub-Last-Rev: a2b25df29ad89452b484bda107a0834d79f09310
GitHub-Pull-Request: golang/sync#18
Reviewed-on: https://go-review.googlesource.com/c/sync/+/429058
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
diff --git a/syncmap/map_test.go b/syncmap/map_test.go
index c883f17..bf69f50 100644
--- a/syncmap/map_test.go
+++ b/syncmap/map_test.go
@@ -115,7 +115,7 @@
 
 	m := new(syncmap.Map)
 	for n := int64(1); n <= mapSize; n++ {
-		m.Store(n, int64(n))
+		m.Store(n, n)
 	}
 
 	done := make(chan struct{})