fixes few more

simple/common.v

 module assert_dff(input clk, input test, input pat);
     always @(posedge clk)
     begin
+        #1;
         if (test != pat)
         begin
             $display("ERROR: ASSERTION FAILED in %m:",$time);
@@ -24,7 +25,7 @@ endmodule
 module assert_Z(input clk, input A);
     always @(posedge clk)
     begin
-        //#1;
+        #1;
         if (A === 1'bZ)
         begin
             $display("ERROR: ASSERTION FAILED in %m:",$time," ",A);
@@ -36,7 +37,7 @@ endmodule
 module assert_X(input clk, input A);
     always @(posedge clk)
     begin
-        //#1;
+        #1;
         if (A === 1'bX)
         begin
             $display("ERROR: ASSERTION FAILED in %m:",$time," ",A);