Most likely the independence vote would have lost, people felt they expressed their rights and Spain would move on to deal with their economy and other matters. Squashing referendums with violence made them look bad and lose the moral ground on the international scale and just embolden the separatists (who wants to live under an oppressive regime anyways).
Also the EU is coming out as a loser in this case. They demonstrated that they basically don't give a fudge about their citizens (which Catalans are), and just want to preserve the political status quo.