Staging: rtl8192e: array overflow in rtl92e_set_swcam()

"EntryNo" is comes from the user in the ioctl and it's a number between
0-255.  The ieee->swcamtable[] array only has 32 elements so it can
result in memory corruption.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>