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/repl/tenant_migration_access_blocker_util.cpp:233: FORWARD_NULL 122671 Calling "this->donorMtab.operator bool()" implies that "this->donorMtab" might be null-like.
/src/mongo/db/repl/tenant_migration_access_blocker_util.cpp:236: FORWARD_NULL 122671 Attempting to access the managed object of an empty smart pointer "this->donorMtab".