fix errors

Author: greg-rychlewski

lib/ecto/adapters/myxql.ex

@@ -555,15 +555,16 @@ defmodule Ecto.Adapters.MyXQL do
       if Path.type(cmd) == :absolute do
         cmd
       else
-        :os.find_executable(cmd) || :erlang.error(:enoent, [command, args, cmd_opts])
+        :os.find_executable(cmd) || :erlang.error(:enoent, [cmd, args, cmd_opts])
       end
 
     port_opts = port_opts(cmd_opts, [args: args])
     port = Port.open({:spawn_executable, cmd}, port_opts)
-    Port.command(port, content)
+    Port.command(port, contents)
+
+    {initial, fun} = Collectable.into("")
 
     try do
-      {initial, fun} = Collectable.into("")
       do_port_byte(port, initial, fun)
     catch
       kind, reason ->