fix: Fixing cookstyle error

linting fix

Signed-off-by: mayankgupta57 <mayank.g57@gmail.com>

Author: mayankgupta57

lib/kitchen/driver/ec2.rb

@@ -586,7 +586,7 @@ def wait_until_ready(server, state)
               # supplied, try to fetch it from the AWS instance
               fetch_windows_admin_password(server, state)
             else
-              output = server.console_output.output || ''
+              output = server.console_output.output || ""
               unless output.nil?
                 output = Base64.decode64(output)
                 debug "Console output: --- \n#{output}"