fix gcc for shell_reverse_tcp payloads on ubuntu

Author: timwr

modules/exploits/linux/local/af_packet_chocobo_root_priv_esc.rb

@@ -93,7 +93,12 @@ def upload_and_chmodx(path, data)
 
   def upload_and_compile(path, data)
     upload "#{path}.c", data
-    output = cmd_exec "gcc -o #{path} #{path}.c -lpthread"
+
+    gcc_cmd = "gcc -o #{path} #{path}.c -lpthread"
+    if session.type.eql? 'shell'
+      gcc_cmd = "PATH=$PATH:/usr/bin/ #{gcc_cmd}"
+    end
+    output = cmd_exec gcc_cmd
 
     unless output.blank?
       print_error output