Fix undefined variable in tomcat_mgr_deploy.rb

Exploit failed (multi/http/tomcat_mgr_deploy): NameError undefined
local variable or method `path' for #<Msf...>
[06/04/2013 10:14:03] [d(3)] core: Call stack:
modules/exploits/multi/http/tomcat_mgr_deploy.rb:253:in `exploit'
lib/msf/core/exploit_driver.rb:205:in `job_run_proc'
lib/msf/core/exploit_driver.rb:166:in `run'
lib/msf/base/simple/exploit.rb:136:in `exploit_simple'
lib/msf/base/simple/exploit.rb:161:in `exploit_simple'
lib/msf/ui/console/command_dispatcher/exploit.rb:111:in `cmd_exploit'
lib/rex/ui/text/dispatcher_shell.rb:427:in `run_command'
lib/rex/ui/text/dispatcher_shell.rb:389:in `block in run_single'
lib/rex/ui/text/dispatcher_shell.rb:383:in `each'
lib/rex/ui/text/dispatcher_shell.rb:383:in `run_single'
lib/rex/ui/text/shell.rb:200:in `run'
lib/msf/ui/web/console.rb:71:in `block in initialize'
lib/msf/core/thread_manager.rb:100:in `call'
lib/msf/core/thread_manager.rb:100:in `block in spawn'

Uses path instead of path_tmp in error messages.