staging: rtl8192e: build warning on HZ

[Randy Dunlap]

FYI:

When CONFIG_HZ=24 (arch/mips/):

../drivers/staging/rtl8192e/rtllib_wx.c: In function 'rtl819x_translate_scan':
../drivers/staging/rtl8192e/rtllib_wx.c:220:57: warning: division by zero [-Wdiv-by-zero]
  220 |                       (jiffies - network->last_scanned) / (HZ / 100));
      |                                                         ^
In file included from ../include/linux/skbuff.h:45,
                 from ../include/linux/if_ether.h:19,
                 from ../include/linux/etherdevice.h:20,
                 from ../drivers/staging/rtl8192e/rtllib_wx.c:18:
../drivers/staging/rtl8192e/rtllib_wx.c: In function 'rtllib_wx_get_scan':
../drivers/staging/rtl8192e/rtllib_wx.c:261:70: warning: division by zero [-Wdiv-by-zero]
  261 |                                    (jiffies - network->last_scanned) /
      |   

-- 
~Randy