staging: rtl8192e: Remove unused rtllib_device::freq_band

Member is never referenced.
Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192e/rtllib.h

@@ -1602,7 +1602,6 @@ struct rtllib_device {
 	int short_slot;
 	int mode;       /* A, B, G */
 	int modulation; /* CCK, OFDM */
-	int freq_band;  /* 2.4Ghz, 5.2Ghz, Mixed */
 
 	/* used for forcing the ibss workqueue to terminate
 	 * without wait for the syncro scan to terminate