crypto: starfive - Correctly handle return of sg_nents_for_len

In the Linux kernel, the following vulnerability has been resolved: crypto: starfive - Correctly handle return of sg_nents_for_len The return value of sg_nents_for_len was assigned to an unsigned long in starfive_hash_digest, causing negative error codes to be converted to large positive integers. Add error checking for sg_nents_for_len and return immediately on failure to prevent potential buffer overflows.