Staging: rtl8192e: array overflow in rtl92e_set_swcam()

"EntryNo" is comes from the user in the ioctl and it's a number between
0-255.  The ieee->swcamtable[] array only has 32 elements so it can
result in memory corruption.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192e/rtl8192e/rtl_cam.c

@@ -78,6 +78,10 @@ void rtl92e_set_swcam(struct net_device *dev, u8 EntryNo, u8 KeyIndex,
 	RT_TRACE(COMP_DBG,
 		 "===========>%s():EntryNo is %d,KeyIndex is %d,KeyType is %d,is_mesh is %d\n",
 		 __func__, EntryNo, KeyIndex, KeyType, is_mesh);
+
+	if (EntryNo >= TOTAL_CAM_ENTRY)
+		return;
+
 	if (!is_mesh) {
 		ieee->swcamtable[EntryNo].bused = true;
 		ieee->swcamtable[EntryNo].key_index = KeyIndex;