libfdt: simplify fdt_node_check_compatible()

Because fdt_stringlist_contains() returns 1 or 0,
fdt_node_check_compatible() can just return the inverted value.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

libfdt/fdt_ro.c

@@ -647,10 +647,8 @@ int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 	prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
 	if (!prop)
 		return len;
-	if (fdt_stringlist_contains(prop, len, compatible))
-		return 0;
-	else
-		return 1;
+
+	return !fdt_stringlist_contains(prop, len, compatible);
 }
 
 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,