iwlegacy: Fix -Wcast-function-type

correct usage prototype of callback in tasklet_init().
Report by https://github.com/KSPP/linux/issues/20Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/intel/iwlegacy/3945-mac.c

@@ -1376,8 +1376,9 @@ il3945_dump_nic_error_log(struct il_priv *il)
 }
 
 static void
-il3945_irq_tasklet(struct il_priv *il)
+il3945_irq_tasklet(unsigned long data)
 {
+	struct il_priv *il = (struct il_priv *)data;
 	u32 inta, handled = 0;
 	u32 inta_fh;
 	unsigned long flags;
@@ -3401,7 +3402,7 @@ il3945_setup_deferred_work(struct il_priv *il)
 	timer_setup(&il->watchdog, il_bg_watchdog, 0);
 
 	tasklet_init(&il->irq_tasklet,
-		     (void (*)(unsigned long))il3945_irq_tasklet,
+		     il3945_irq_tasklet,
 		     (unsigned long)il);
 }
 

drivers/net/wireless/intel/iwlegacy/4965-mac.c

@@ -4343,8 +4343,9 @@ il4965_synchronize_irq(struct il_priv *il)
 }
 
 static void
-il4965_irq_tasklet(struct il_priv *il)
+il4965_irq_tasklet(unsigned long data)
 {
+	struct il_priv *il = (struct il_priv *)data;
 	u32 inta, handled = 0;
 	u32 inta_fh;
 	unsigned long flags;
@@ -6237,7 +6238,7 @@ il4965_setup_deferred_work(struct il_priv *il)
 	timer_setup(&il->watchdog, il_bg_watchdog, 0);
 
 	tasklet_init(&il->irq_tasklet,
-		     (void (*)(unsigned long))il4965_irq_tasklet,
+		     il4965_irq_tasklet,
 		     (unsigned long)il);
 }