Fixup syntax error

Author: HoloRin

private/app_file.bzl

@@ -35,7 +35,7 @@ def _impl(ctx):
         registered_list = ""
 
     applications_list = ""
-    if src == "" or len(ctx.attr.extra_apps > 0) or len(ctx.attr.deps) > 0:
+    if src == "" or len(ctx.attr.extra_apps) > 0 or len(ctx.attr.deps) > 0:
         applications = ["kernel", "stdlib"] + ctx.attr.extra_apps
         for dep in ctx.attr.deps:
             applications.append(dep[ErlangAppInfo].app_name)