Dereference of potentially null field

If the field is actually null, then a null pointer dereference will occur. Field, which is statistically checked against null, is dereferenced.
/src/mongo/db/exec/sbe/stages/column_scan.cpp:636: NULL_FIELD 175083 Reading field "_rowStoreCursor", which is expected to possibly be "nullptr" in "this->_rowStoreCursor" (checked 8 out of 10 times).
/src/mongo/db/exec/sbe/stages/column_scan.cpp:636: NULL_FIELD 175083 Attempting to access the managed object of an empty smart pointer "this->_rowStoreCursor".