wifi: ath11k: fix potential buffer underflow in ath11k_hal_rx_msdu_list_get()

wifi: ath11k: fix potential buffer underflow in ath11k_hal_rx_msdu_list_get()

When the first entry in msdu_details has a zero buffer address,
the code accesses msdu_details[i - 1] with i == 0, causing a
buffer underflow.

Fix similarly to ath12k_wifi7_hal_rx_msdu_list_get() by adding
a separate check for i == 0 before the main condition to prevent
the out-of-bounds access.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Dmitry Morgun <d.morgun@ispras.ru>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260530114252.42615-1-d.morgun@ispras.ru
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>