staging: vt6656: Correct a few assignments to be compares in iwctl_siwencodeext()

The result of "foo = bar" is true, so in statements such as
  ...
  if((pDevice->bwextstep0 = TRUE)&&(param->u.wpa_key.key_index ==1))
  ...
an assignment  is most likely not what was intended - a comparison was. As in:
  ...
  if ((pDevice->bwextstep0 == TRUE) && (param->u.wpa_key.key_index == 1))
  ...

There are a 3 such mistakes in the iwctl_siwencodeext() function.
This patch fixes them all.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>