CDRIVER-1522 use llabs for int64 in mongoc-cursor.c
CDRIVER-1522 use llabs for int64 in mongoc-cursor.c

Convey-Compliance/mongo-c-driver,Convey-Compliance/mongo-c-driver,Convey-Compliance/mongo-c-driver,Convey-Compliance/mongo-c-driver,Convey-Compliance/mongo-c-driver