client: remove toPlatforms()

Just use apitypes.OCIPlatformFromProto().

Suggested-by: Jin Dong <djdongjin95@gmail.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

client/client.go

@@ -953,22 +953,10 @@ func (c *Client) GetSnapshotterSupportedPlatforms(ctx context.Context, snapshott
 	}
 
 	sn := resp.Plugins[0]
-	snPlatforms := toPlatforms(sn.Platforms)
+	snPlatforms := apitypes.OCIPlatformFromProto(sn.Platforms)
 	return platforms.Any(snPlatforms...), nil
 }
 
-func toPlatforms(pt []*apitypes.Platform) []ocispec.Platform {
-	platforms := make([]ocispec.Platform, len(pt))
-	for i, p := range pt {
-		platforms[i] = ocispec.Platform{
-			Architecture: p.Architecture,
-			OS:           p.OS,
-			Variant:      p.Variant,
-		}
-	}
-	return platforms
-}
-
 // GetSnapshotterCapabilities returns the capabilities of a snapshotter.
 func (c *Client) GetSnapshotterCapabilities(ctx context.Context, snapshotterName string) ([]string, error) {
 	filters := []string{fmt.Sprintf("type==%s, id==%s", plugins.SnapshotPlugin, snapshotterName)}