wifi: ath12k: check M3 buffer size as well whey trying to reuse it

Currently in recovery/resume cases, we do not free M3 buffer but
instead will reuse it. This is done by checking m3_mem->vaddr: if it
is not NULL we believe M3 buffer is ready and go ahead to reuse it.

Note that m3_mem->size is not checked. This is safe for now because
currently M3 reuse logic only gets executed in recovery/resume cases
and the size keeps unchanged in either of them.

However ideally the size should be checked as well, to make the code
safer. So add the check there. Now if that check fails, free old M3
buffer and reallocate a new one.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30

Fixes: 303c0178 ("wifi: ath12k: fix kernel crash during resume")
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240425021740.29221-1-quic_bqiang@quicinc.com