MINOR: samples: data assignation simplification

With the difference between the "struct sample" data and the
"struct sample_storage" data, it was not possible to write
data = data, and we did a memcpy. This patch remove some of
these memcpy.
diff --git a/src/map.c b/src/map.c
index 73e057e..577d418 100644
--- a/src/map.c
+++ b/src/map.c
@@ -161,9 +161,8 @@
 	if (pat) {
 		/* Copy sample. */
 		if (pat->data) {
-			smp->data.type = pat->data->type;
+			smp->data = *pat->data;
 			smp->flags |= SMP_F_CONST;
-			memcpy(&smp->data.u, &pat->data->u, sizeof(smp->data.u));
 			return 1;
 		}