media: atomisp: Add check for rgby_data memory allocation failure

In the Linux kernel, the following vulnerability has been resolved: media: atomisp: Add check for rgby_data memory allocation failure In ia_css_3a_statistics_allocate(), there is no check on the allocation result of the rgby_data memory. If rgby_data is not successfully allocated, it may trigger the assert(host_stats->rgby_data) assertion in ia_css_s3a_hmem_decode(). Adding a check to fix this potential issue.