drm/amdgpu: Check for multiplication overflow in checkpoint stack size

drm/amdgpu: Check for multiplication overflow in checkpoint stack size

get_checkpoint_info() in kfd_mqd_manager_v9.c finds 32-bit value
ctl_stack_size by multiplying two 32-bit values. This can overflow to a
lower value, which could result in copying outside the bounds of
a buffer in checkpoint_mqd() in the same file.

Put in a check for the overflow, and fail with -EINVAL if detected.

v2: use check_mul_overflow()

Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>