[otbn,dv] Fix wait for valid instruction in `otbn_ctrl_redun_vseq`

Signed-off-by: Andreas Kurth <adk@lowrisc.org>
diff --git a/hw/ip/otbn/dv/uvm/env/seq_lib/otbn_ctrl_redun_vseq.sv b/hw/ip/otbn/dv/uvm/env/seq_lib/otbn_ctrl_redun_vseq.sv
index de19cbe..df8c7eb 100644
--- a/hw/ip/otbn/dv/uvm/env/seq_lib/otbn_ctrl_redun_vseq.sv
+++ b/hw/ip/otbn/dv/uvm/env/seq_lib/otbn_ctrl_redun_vseq.sv
@@ -115,7 +115,7 @@
           do begin
             @(cfg.clk_rst_vif.cb);
             uvm_hdl_read("tb.dut.u_otbn_core.insn_valid", insn_valid);
-          end while(insn_valid);
+          end while(!insn_valid);
         )
         `DV_CHECK_STD_RANDOMIZE_WITH_FATAL(choose_err, choose_err inside {[0:2]};)
         case(choose_err)