dtc: Use streq() in preference to strcmp()

dtc defines a streq() (string equality) macro to avoid the easy confusion
of the sense of strcmp() comparison for equality.  A few places where we
don't use it have slipped in, so remove them.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

checks.c

@@ -325,7 +325,7 @@ static void check_property_name_chars_strict(struct check *c,
 			continue;
 
 		/* Certain names are whitelisted */
-		if (strcmp(name, "device_type") == 0)
+		if (streq(name, "device_type"))
 			continue;
 
 		/*

livetree.c

@@ -242,7 +242,7 @@ void delete_property_by_name(struct node *node, char *name)
 	struct property *prop = node->proplist;
 
 	while (prop) {
-		if (!strcmp(prop->name, name)) {
+		if (streq(prop->name, name)) {
 			delete_property(prop);
 			return;
 		}
@@ -275,7 +275,7 @@ void delete_node_by_name(struct node *parent, char *name)
 	struct node *node = parent->children;
 
 	while (node) {
-		if (!strcmp(node->name, name)) {
+		if (streq(node->name, name)) {
 			delete_node(node);
 			return;
 		}