feat(fall.lua): change the way denops-lazy is loaded

The previous implementation was passing the spec.name to the
denops-lazy load function. This commit changes that to directly
pass the string "fall". This makes the code more explicit and
avoids potential issues with spec.name not being what we expect.

nvim/lua/plugin/fall.lua

@@ -6,7 +6,7 @@ return {
 	dependencies = {
 		"vim-denops/denops.vim",
 	},
-	config = function(spec)
-		require("denops-lazy").load(spec.name)
+	config = function()
+		require("denops-lazy").load("fall")
 	end,
 }