Determine if an object can be found in the object database by an abbreviated object ID.
The full OID of the found object if just one is found.
The database to be searched for the given object.
A prefix of the id of the object to read.
The length of the prefix.
0 if found, GIT_ENOTFOUND if not found, GIT_EAMBIGUOUS if multiple matches were found, other value < 0 if there was a read error.