staging: vchiq_core: Bail out in case of invalid tx_pos

Properly handle the error case in case of an invalid tx_pos.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c

@@ -600,8 +600,10 @@ reserve_space(VCHIQ_STATE_T *state, size_t space, int is_blocking)
 				return NULL; /* No space available */
 		}
 
-		BUG_ON(tx_pos ==
-			(state->slot_queue_available * VCHIQ_SLOT_SIZE));
+		if (tx_pos == (state->slot_queue_available * VCHIQ_SLOT_SIZE)) {
+			pr_warn("%s: invalid tx_pos: %d\n", __func__, tx_pos);
+			return NULL;
+		}
 
 		slot_index = local->slot_queue[
 			SLOT_QUEUE_INDEX_FROM_POS(tx_pos) &