staging: rtl8188eu: replace subtraction with result

Replace subtraction with the result to improve readability and
clear missing spaces around '-' checkpatch issues.
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_cmd.c

@@ -405,10 +405,10 @@ u8 rtw_joinbss_cmd(struct adapter  *padapter, struct wlan_network *pnetwork)
 
 	psecuritypriv->authenticator_ie[0] = (unsigned char)psecnetwork->ie_length;
 
-	if ((psecnetwork->ie_length-12) < (256-1))
+	if ((psecnetwork->ie_length-12) < 255)
 		memcpy(&psecuritypriv->authenticator_ie[1], &psecnetwork->ies[12], psecnetwork->ie_length-12);
 	else
-		memcpy(&psecuritypriv->authenticator_ie[1], &psecnetwork->ies[12], (256-1));
+		memcpy(&psecuritypriv->authenticator_ie[1], &psecnetwork->ies[12], 255);
 
 	psecnetwork->ie_length = 0;
 	/*  Added by Albert 2009/02/18 */