Cygwin: Revert attempting to unload user profile after use

Revert "Cywin: user profile: unload impersonation user profile on exit"
Revert "Cygwin: seteuid: allow inheriting impersonation user profile handle"
Revert "Cygwin: user profile: add debug output to unload_user_profile"
Revert "Cygwin: user profile: Make an effort to unload unused user profiles"

This reverts commit bcb33dc4f0.
This reverts commit dd3730ed9c.
This reverts commit 8eee25241e.
This reverts commit 71b8777a71.

This patchset actually results in the following problem:

- After a couple of ssh logon/logoff attempts, an interactive session
  of the same user loging in, is broken.

Apparently UnloadUserProfile manages to unload the user's profile
even while a parallel interactive session still uses the user's
profile.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/sec_auth.cc

@@ -316,15 +316,6 @@ load_user_profile (HANDLE token, struct passwd *pw, cygpsid &usersid)
   return pi.hProfile;
 }
 
-bool
-unload_user_profile (HANDLE token, HANDLE profile)
-{
-  bool ret = UnloadUserProfile (token, profile);
-  if (!ret)
-    debug_printf ("UnloadUserProfile, %E");
-  return ret;
-}
-
 HANDLE
 lsa_open_policy (PWCHAR server, ACCESS_MASK access)
 {