radv: Fix creating accel structs with unbound buffers
If the buffer hasn't been bound to memory yet, we will dereference a
NULL pointer in radv_CreateAccelerationStructureKHR.
cc: mesa-stable
Closes: #8199
If the buffer hasn't been bound to memory yet, we will dereference a
NULL pointer in radv_CreateAccelerationStructureKHR.
cc: mesa-stable
Closes: #8199