Revert "Land #15199, Improve the get_processes API"

This reverts commit 0203989, reversing
changes made to 0ca3dbc.

lib/msf/core/post/common.rb

@@ -2,8 +2,6 @@
 
 module Msf::Post::Common
 
-  include Msf::Post::File
-
   def initialize(info = {})
     super(update_info(
       info,

lib/msf/core/post/linux/priv.rb

@@ -41,6 +41,21 @@ def cp_cmd(origin_file, final_file)
     cmd_exec("echo '#{file_origin}' > #{final_file}")
   end
 
+  def pids()
+    dir_proc = "/proc/"
+    pids = []
+
+    directories_proc = dir(dir_proc)
+    directories_proc.each do |elem|
+      elem.gsub( / *\n+/, "")
+      if elem[-1] == '1' || elem[-1] == '2' || elem[-1] == '3' || elem[-1] == '4' || elem[-1] == '5' || elem[-1] == '6' || elem[-1] == '7' || elem[-1] == '8' || elem[-1] == '9' || elem[-1] == '0'
+        pids.insert(-1, elem)
+      end
+    end
+
+    return pids.sort_by(&:to_i)
+  end
+
   def binary_of_pid(pid)
     binary = read_file("/proc/#{pid}/cmdline")
     if binary == "" #binary.empty?