It turns out making many CPU cores working with a single ringbuf has a
potential deadlock hazard, especially visible on RT kernels. To avoid
even a slightest danger, reduce ringbuf size instead. In the new
scenario if we do not fit into the total ringbuf size, the size of each
individual ringbuf will be adjusted and aligned for readability.

Currently used int type is not enough when it comes to values like a few
GiB, expressed in the number of bytes, making it impossible to set some
reasonable values. Use long type for ROX_COLLECTOR_SINSP_BUFFER_SIZE,
ROX_COLLECTOR_SINSP_TOTAL_BUFFER_SIZE,
ROX_COLLECTOR_SINSP_THREAD_CACHE_SIZE.