rm active should fail

[cire831]

consider the following state:

dvt5 (120): tree sys
sys
├── active
│   └── 0.4.7021
├── backup
│   └── 0.4.7018
├── golden
│   └── 0.4.7020
├── nib
│   └── 0.4.7021
├── rtc
└── running
    └── 0.4.7021

5 directories, 6 files
dvt5 (121): ll -a sd/0/img
total 0
drwxr-x--x 5 pi pi 0 Dec 31  1969 ./
drwxr-x--x 5 pi pi 0 Dec 31  1969 ../
-rw-rw-r-- 1 pi pi 0 Aug 12 18:55 0.4.7018
-rw-rw-r-- 1 pi pi 0 Aug 12 18:55 0.4.7019
-rw-rw-r-- 1 pi pi 0 Aug 12 18:55 0.4.7021
dvt5 (122): 

now we try rm sd/0/img/0.4.7021. This is the active and should fail. The code on the tag side says it is returning EINVAL if the active is being deleted (see ImageManager.delete()).

On the base station side, the command simply returns. Behaves like it is happy which how things went.