fix for libreelec 12.0.2

[dawez]

After the update to libreelec 12.0.2. I was getting an error on start:

Traceback (most recent call last):
  File "/usr/bin/bcmstat.sh", line 1708, in <module>
    main(sys.argv[1:])
  File "/usr/bin/bcmstat.sh", line 1565, in main
    sysinfo = getsysinfo(HARDWARE)
              ^^^^^^^^^^^^^^^^^^^^
  File "/usr/bin/bcmstat.sh", line 770, in getsysinfo
    VCG_INT = vcgencmd_items("get_config int", isInt=True)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/bin/bcmstat.sh", line 375, in vcgencmd_items
    elif l[1][:2] == "0x":
         ~^^^
IndexError: list index out of range

This PR fixes the issue so the script is runnable again. It looks that the values are displayed as before. A bit more debug shown that the case where l has length less than 2 are:

['ioctl_set_msg failed:-1']
['get_config int']
['ioctl_set_msg failed:-1']
['get_config int']

This is on an Rpi3