When looking for longest matching soname substring, we don't copy enough
diff --git a/output.c b/output.c
index 6597e89..edf4522 100644
--- a/output.c
+++ b/output.c
@@ -200,7 +200,7 @@
 	if (lib->protolib == NULL) {
 		size_t sz = strlen(lib->soname);
 		char buf[sz + 1];
-		memcpy(buf, lib->soname, sz);
+		memcpy(buf, lib->soname, sz + 1);
 
 		do {
 			if (protolib_cache_maybe_load(&g_protocache, buf, 0,