rubocop: Drop "r" from Naming/MethodParameterName allowlist

- This stands for "resource" in our case, so use the long name.

Library/.rubocop.yml

@@ -201,7 +201,6 @@ Naming/MethodParameterName:
       "o",
       "p",
       "pr",
-      "r",
     ]
 
 # Both styles are used depending on context,

Library/Homebrew/cmd/fetch.rb

@@ -130,12 +130,12 @@ module Homebrew
     end
   end
 
-  def self.fetch_resource(r, args:)
-    puts "Resource: #{r.name}"
-    fetch_fetchable r, args: args
+  def self.fetch_resource(resource, args:)
+    puts "Resource: #{resource.name}"
+    fetch_fetchable resource, args: args
   rescue ChecksumMismatchError => e
-    retry if retry_fetch?(r, args: args)
-    opoo "Resource #{r.name} reports different sha256: #{e.expected}"
+    retry if retry_fetch?(resource, args: args)
+    opoo "Resource #{resource.name} reports different sha256: #{e.expected}"
   end
 
   def self.fetch_formula(f, args:)