Coverity analysis defect 116412: Dereference after null check

Dereference after null check

Either the check against null is unnecessary, or there may be a null pointer dereference. Pointer is checked against null but then dereferenced anyway
/src/mongo/db/catalog/create_collection.cpp:287: FORWARD_NULL 116412 Comparing "db" to null implies that "db" might be null.
/src/mongo/db/catalog/create_collection.cpp:294: FORWARD_NULL 116412 Passing null pointer "db" to "makeUniqueCollectionNamespace", which dereferences it. (The dereference happens because this is a virtual function call.)