wifi: ath12k: Fix buffer overflow in debugfs

[ Upstream commit 8c7a5031 ]

If the user tries to write more than 32 bytes then it results in memory
corruption.  Fortunately, this is debugfs so it's limited to root users.

Fixes: 3f73c24f ("wifi: ath12k: Add support to enable debugfs_htt_stats")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/35daefbd-d493-41d9-b192-96177d521b40@stanley.mountain


Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>