misc: st_core: Do not call kfree_skb() under spin_lock_irqsave()

It is not allowed to call kfree_skb() from hardware interrupt
context or with hardware interrupts being disabled.
So replace kfree_skb() with dev_kfree_skb_irq() under
spin_lock_irqsave(). Compile tested only.

Fixes: 53618cc1e51e ("Staging: sources for ST core")
Signed-off-by: Jinjie Ruan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/ti-st/st_core.c

···
 #include <linux/skbuff.h>
 
 #include <linux/ti_wilink_st.h>
+#include <linux/netdevice.h>
 
 /*
  * function pointer pointing to either,
···
 	case ST_LL_AWAKE_TO_ASLEEP:
 		pr_err("ST LL is illegal state(%ld),"
 			   "purging received skb.", st_ll_getstate(st_gdata));
-		kfree_skb(skb);
+		dev_kfree_skb_irq(skb);
 		break;
 	case ST_LL_ASLEEP:
 		skb_queue_tail(&st_gdata->tx_waitq, skb);
···
 	default:
 		pr_err("ST LL is illegal state(%ld),"
 			   "purging received skb.", st_ll_getstate(st_gdata));
-		kfree_skb(skb);
+		dev_kfree_skb_irq(skb);
 		break;
 	}
 
···
 				spin_unlock_irqrestore(&st_data->lock, flags);
 				break;
 			}
-			kfree_skb(skb);
+			dev_kfree_skb_irq(skb);
 			spin_unlock_irqrestore(&st_data->lock, flags);
 		}
 		/* if wake-up is set in another context- restart sending */