staging: wlan-ng: Remove unused struct wlan_ie_tim references

Pointer reference to struct wlan_ie_tim is added as a member
variable of a structure; However, this references is never
used. Remove such unused struct reference. The cleanup also
renders the struct useless; so remove it as well.
Issue identified as part of coccicheck based code analysis.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Deepak R Varma <drv@mailo.com>
Link: https://lore.kernel.org/r/36834007587a2e0ef7a782f5919f3a4c756b7840.1667308828.git.drv@mailo.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>