It is clear that a piece of cleaning equipment in a Walgreens drug store aisle injured a woman’s back.What’s not clear, however, is whether that machine presented an open and obvious danger to her. On that basis, a split 1st District appeals panel ruled Saime Sebnem Bulduk can pursue her negligence case against the pharmacy chain.The panel’s opinion, issued Monday, reverses a Cook County judge’s order granting summary judgment to Walgreen Co. and remands Bulduk’s case to the circuit court to …