By Nivedita Balu (Reuters) -Elon Musk warned Twitter Inc on Monday that he might walk away from his $44 billion deal to acquire the social media company if it fails to provide the data on spam and fake accounts that he seeks. This was not the first time Musk had suggested publicly his acquisition of Twitter may not happen. But the warning, delivered in a letter from Musk’s lawyers to Twitter’s chief legal officer, Vijaya Gadde, marked an escalation. It accused Twitter of being in “material breach” of its deal obligations. Musk’s threats to tear up the deal have coincided with the share plunges…