Update fuzz_seconds.sh

fuzz_seconds.sh

 #!/usr/bin/env bash
 
-fuzz_seconds=${1:-10} # 10 seconds by default
+fuzz_seconds=${2:-10} # 10 seconds by default
 echo "Going to fuzz for $fuzz_seconds seconds."
 
 set -e
 
-afl-fuzz -i in -o out -- ./fuzz_calc &
+afl-fuzz -i in -o out -- $1 &
 afl_pid=$!
 
 sleep $fuzz_seconds