fix a few more rubocop offenses

lib/liquid/block.rb

@@ -7,7 +7,7 @@ module Liquid
 
     def parse(tokens)
       @body = BlockBody.new
-      while more = parse_body(@body, tokens)
+      while parse_body(@body, tokens)
       end
     end
 

lib/liquid/drop.rb

@@ -57,8 +57,6 @@ module Liquid
 
     alias_method :[], :invoke_drop
 
-    private
-
     # Check for method existence without invoking respond_to?, which creates symbols
     def self.invokable?(method_name)
       invokable_methods.include?(method_name.to_s)

lib/liquid/standardfilters.rb

@@ -138,7 +138,6 @@ module Liquid
     # Remove duplicate elements from an array
     # provide optional property with which to determine uniqueness
     def uniq(input, property = nil)
-      ary = InputIterator.new(input)
       if property.nil?
         input.uniq
       elsif input.first.respond_to?(:[])

lib/liquid/tags/case.rb

@@ -16,7 +16,7 @@ module Liquid
 
     def parse(tokens)
       body = BlockBody.new
-      while more = parse_body(body, tokens)
+      while parse_body(body, tokens)
         body = @blocks.last.attachment
       end
     end

lib/liquid/variable.rb

@@ -41,11 +41,10 @@ module Liquid
       if filter_markup =~ /#{FilterSeparator}\s*(.*)/om
         filters = $1.scan(FilterParser)
         filters.each do |f|
-          if f =~ /\w+/
-            filtername = Regexp.last_match(0)
-            filterargs = f.scan(/(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o).flatten
-            @filters << parse_filter_expressions(filtername, filterargs)
-          end
+          next unless f =~ /\w+/
+          filtername = Regexp.last_match(0)
+          filterargs = f.scan(/(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o).flatten
+          @filters << parse_filter_expressions(filtername, filterargs)
         end
       end
     end
@@ -74,7 +73,7 @@ module Liquid
     def render(context)
       @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
         filter_args = evaluate_filter_expressions(context, filter_args, filter_kwargs)
-        output = context.invoke(filter_name, output, *filter_args)
+        context.invoke(filter_name, output, *filter_args)
       end.tap{ |obj| taint_check(obj) }
     end