wifi: ath11k: fix use after free in ath11k_dp_rx_msdu_coalesce()

wifi: ath11k: fix use after free in ath11k_dp_rx_msdu_coalesce()

In ath11k_dp_rx_msdu_coalesce() the loop uses ->is_continuation after
the dev_kfree_skb_any(). This can cause a use after free kfence.

Use flag for caching is_continuation for use after the
dev_kfree_skb_any().

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Willmar Knikker <willmar@met-dubbel-l.nl>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Link: https://patch.msgid.link/20260505171709.547274-1-willmar@met-dubbel-l.nl
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>