staging: rtl8188eu: don't cast when calling rtw_set_fixed_ie()

The 'pbuf' and 'source' arguments to rtw_set_fixed_ie() are (void *), the
explicit typecasts are not needed. They just make code less readable.

Also fix checkpatch issues in the lines touched:
  ERROR: space prohibited before that ',' (ctx:WxW)
  WARNING: line over 80 characters
  CHECK: Unnecessary parentheses around <var>

Note: some of the modified lines are still over 80 characters because they
are not fixable by just adding newlines. They will be fixed in a later
patch.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>