Dereference before null check

There may be a null pointer dereference, or else the comparison against null is unnecessary. All paths that lead to this null pointer comparison already dereference the pointer earlier
/src/mongo/db/pipeline/sharded_agg_helpers.cpp:1006: REVERSE_INULL 123004 Directly dereferencing pointer "pipeline".
/src/mongo/db/pipeline/sharded_agg_helpers.cpp:1066: REVERSE_INULL 123004 Null-checking "pipeline" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.