CLEANUP: Use ist2(const void*, size_t) whenever possible

Refactoring performed with the following Coccinelle patch:

    @@
    struct ist i;
    expression p, l;
    @@

    - i.ptr = p;
    - i.len = l;
    + i = ist2(p, l);
diff --git a/src/mux_h1.c b/src/mux_h1.c
index 5ff3d54..0ee4772 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -3585,8 +3585,7 @@
 	}
 
 	entry->node.key = strdup(from);
-	entry->name.ptr = strdup(to);
-	entry->name.len = strlen(to);
+	entry->name = ist2(strdup(to), strlen(to));
 	if (!entry->node.key || !entry->name.ptr) {
 		free(entry->node.key);
 		istfree(&entry->name);