Revert "Staging: drivers: rtl8188eu: use sizeof(*ptr) instead of sizeof(struct)"

This reverts commit 99aded71 ("Staging: drivers: rtl8188eu: use
sizeof(*ptr) instead of sizeof(struct)").

This commit is wrong, as adapt->HalData has a type of "void *", so
now we are allocating a much to small struct, which causes the driver
to overwrite random memory which leads to a non working driver and
various system crashes.

Cc: Jacky Boen <aqiank@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>