Staging: rtl8192e: Fix declaration of symbols

The two declarations with issues in rtl_wx.h:

  * function: struct iw_statistics *r8192_get_wireless_stats();
  * variable: extern struct iw_handler_def r8192_wx_handlers_def;

The symbol 'r8192_get_wireless_stats' is declared as 'extern'
but it is only used in the local scope. The declaration is deleted
of rtl_wx.h, fixing the conflict with the 'extern' and 'static' scope.

The symbol 'r8192_wx_handlers_def' was fixed of some issues related
to variable declaration marked as 'extern' implicitly,
causing this sparse warning:

drivers/staging/rtl8192e/rtl8192e/rtl_wx.c:1323:24: warning: symbol
'r8192_wx_handlers_def' was not declared. Should it be static?

Resolved incluing the fixed header to rtl_wx.c

Also, isn't declared as constant variable, so it declared as such.
And delete unnecessary cast in rtl_core.c.
Signed-off-by: Joel Pelaez Jorge <joelpelaez@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192e/rtl8192e/rtl_core.c

@@ -2926,8 +2926,7 @@ static int rtl8192_pci_probe(struct pci_dev *pdev,
 
 	dev->netdev_ops = &rtl8192_netdev_ops;
 
-	dev->wireless_handlers = (struct iw_handler_def *)
-				 &r8192_wx_handlers_def;
+	dev->wireless_handlers = &r8192_wx_handlers_def;
 	dev->ethtool_ops = &rtl819x_ethtool_ops;
 
 	dev->type = ARPHRD_ETHER;

drivers/staging/rtl8192e/rtl8192e/rtl_wx.c

@@ -19,6 +19,7 @@
 
 #include <linux/string.h>
 #include "rtl_core.h"
+#include "rtl_wx.h"
 
 #define RATE_COUNT 12
 static u32 rtl8192_rates[] = {
@@ -1320,7 +1321,7 @@ static struct iw_statistics *r8192_get_wireless_stats(struct net_device *dev)
 	return wstats;
 }
 
-struct iw_handler_def  r8192_wx_handlers_def = {
+const struct iw_handler_def r8192_wx_handlers_def = {
 	.standard = r8192_wx_handlers,
 	.num_standard = ARRAY_SIZE(r8192_wx_handlers),
 	.private = r8192_private_handler,

drivers/staging/rtl8192e/rtl8192e/rtl_wx.h

@@ -24,8 +24,7 @@ struct net_device;
 struct iw_handler_def;
 struct iw_statistics;
 
-extern struct iw_handler_def r8192_wx_handlers_def;
-struct iw_statistics *r8192_get_wireless_stats(struct net_device *dev);
+extern const struct iw_handler_def r8192_wx_handlers_def;
 u16 rtl8192_11n_user_show_rates(struct net_device *dev);
 
 #endif