rocksdb: pedantic error checks that could just be direct returns

[odeke-em]

If we examine the code in RocksDB, we can see this pedantic pattern that could instead be a direct return

[faddat]

• nice commentary
• nice use of ipad
• agree

but the key thing is that we don't use rocksdb v7

[odeke-em]

Thanks @faddat for the reply and for fixing this issue. Ahah nice that you noticed it was an iPad