[PATCH] rawdev: fix device ID retrieval function prototype

[Nawal Kishor]

>> Fixed rte_rawdev_get_dev_id() function prototype and its usage.
>
>What? Why?

>[...]
>> -uint16_t
>> +int
>>  rte_rawdev_get_dev_id(const char *name);

>Other functions handle dev_id as uint16_t, so why changing this function?

The spec says that rte_rawdev_get_dev_id() returns negative number in case of failure.
But in the definition it is returning uint16_t which will never be negative, hence changed it to int.

If this is not acceptable, what fix will you suggest?