Remove unnecessary conditions for Fiddle::TYPE_VARIADIC (#547)

Author: nobu

lib/reline/terminfo.rb

@@ -31,21 +31,7 @@ def self.curses_dl_files
   @curses_dl = false
   def self.curses_dl
     return @curses_dl unless @curses_dl == false
-    if RUBY_VERSION >= '3.0.0'
-      # Gem module isn't defined in test-all of the Ruby repository, and
-      # Fiddle in Ruby 3.0.0 or later supports Fiddle::TYPE_VARIADIC.
-      fiddle_supports_variadic = true
-    elsif Fiddle.const_defined?(:VERSION,false) and Gem::Version.create(Fiddle::VERSION) >= Gem::Version.create('1.0.1')
-      # Fiddle::TYPE_VARIADIC is supported from Fiddle 1.0.1.
-      fiddle_supports_variadic = true
-    else
-      fiddle_supports_variadic = false
-    end
-    if fiddle_supports_variadic and not Fiddle.const_defined?(:TYPE_VARIADIC)
-      # If the libffi version is not 3.0.5 or higher, there isn't TYPE_VARIADIC.
-      fiddle_supports_variadic = false
-    end
-    if fiddle_supports_variadic
+    if Fiddle.const_defined?(:TYPE_VARIADIC)
       curses_dl_files.each do |curses_name|
         result = Fiddle::Handle.new(curses_name)
       rescue Fiddle::DLError