wifi: ath12k: Fix for out-of bound access error

wifi: ath12k: Fix for out-of bound access error

Selfgen stats are placed in a buffer using print_array_to_buf_index() function.
Array length parameter passed to the function is too big, resulting in possible
out-of bound memory error.
Decreasing buffer size by one fixes faulty upper bound of passed array.

Discovered in coverity scan, CID 1600742 and CID 1600758

Signed-off-by: Karol Przybylski <karprzy7@gmail.com>
Acked-by: Kalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20241105101132.374372-1-karprzy7@gmail.com
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>