lib/memrange: Skip 0-sized resources.

Change-Id: I44194153817b8e6b641e407fc4a9e0fd5bc3f318
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/5152
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/lib/memrange.c

@@ -258,6 +258,9 @@ static void collect_ranges(void *gp, struct device *dev, struct resource *res)
 {
 	struct collect_context *ctx = gp;
 
+	if (res->size == 0)
+		return;
+
 	memranges_insert(ctx->ranges, res->base, res->size, ctx->tag);
 }