Vin Diesel loves when the "Fast & Furious" family comes together. Diesel spoke with ET's Matt Cohen on Saturday at the block party for Charlize Theron's Africa Outreach project in Los Angeles, where he reacted to the shocking "Fast X" credits scene, which features Dwayne Johnson's return to the franchise as Agent Luke Hobbs. Following a social media spat between Diesel and Johnson, Johnson vowed…