staging: rtl8723bs: os_dep: fix spelling mistake "offet" -> "offset"

There is a spelling mistake in a DBG_871X error message. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190916092211.32646-1-colin.king@canonical.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/os_dep/ioctl_linux.c

@@ -2786,7 +2786,7 @@ static int rtw_dbg_port(struct net_device *dev,
 
 					DBG_871X("oper_ch =%d\n", rtw_get_oper_ch(padapter));
 					DBG_871X("oper_bw =%d\n", rtw_get_oper_bw(padapter));
-					DBG_871X("oper_ch_offet =%d\n", rtw_get_oper_choffset(padapter));
+					DBG_871X("oper_ch_offset =%d\n", rtw_get_oper_choffset(padapter));
 
 					break;
 				case 0x05: