[spandsp] scan-build: Division by zero - test_cadence()

libs/spandsp/src/super_tone_rx.c

@@ -170,6 +170,7 @@ static int test_cadence(super_tone_rx_segment_t *pattern,
                 return 0;
             }
         }
+        if (steps) 
             j = (rotation + steps - 1)%steps;
         if (pattern[j].f1 != test[9].f1  ||  pattern[j].f2 != test[9].f2)
             return 0;