(debtor's placement of crop sale proceeds in personal bank account and used to pay living expenses and farm labor costs constituted willful and/or malicious injury to creditor who had prior perfected security interest in crop and crop proceeds; result was that debt non-dischargeable under 11 U.S.C. Sec. 523(a)(6); debtor knew that he owed money to creditor and knew that crops served as security for the debt and that he was to use crop sale proceeds to repay loan from creditor).