various: update CaskLoader.load() reference

Casks/i/ibabel.rb

@@ -13,7 +13,7 @@ cask "ibabel" do
     strategy :page_match do |page, regex|
       match = page.match(regex)
 
-      cask = CaskLoader.load("ibabel")
+      cask = CaskLoader.load(__FILE__)
       download_url = "https://macinchem.org/wp-content/uploads/#{match[1]}/#{match[2]}/iBabel.zip"
       app_version = Homebrew::Livecheck::Strategy::ExtractPlist.find_versions(cask: cask,
                                                                               url:  download_url)[:matches].values.max

Casks/r/redquits.rb

@@ -15,7 +15,7 @@ cask "redquits" do
       major_version = page[regex, 1]
       next if major_version.blank?
 
-      cask = CaskLoader.load("redquits")
+      cask = CaskLoader.load(__FILE__)
       download_url = "http://redquits.s3.amazonaws.com/RedQuits_v#{major_version}.pkg"
       Homebrew::Livecheck::Strategy::ExtractPlist.find_versions(cask: cask, url: download_url)[:matches].values
     end

Casks/s/smultron.rb

@@ -14,7 +14,7 @@ cask "smultron" do
       major_version = page[regex, 1]
       next if major_version.blank?
 
-      cask = CaskLoader.load("smultron")
+      cask = CaskLoader.load(__FILE__)
       download_url = "https://www.peterborgapps.com/downloads/Smultron#{major_version}.zip"
       Homebrew::Livecheck::Strategy::ExtractPlist.find_versions(cask: cask, url: download_url)[:matches].values
     end