illumos gate

1. We allocate memory chunk with size MAXMODCONFNAME, but then we do copy data into it by strlen(optarg), replace bcopy by strlcpy.
2. strncmp() does compare n chars, that will allow to use names by prefix. Since with strlcpy we do have zero terminated strings, use normal strcmp.
3. the whole if strncmp() statement does not work:

the expression there should look like:

if (!((strncmp(drvlimit, "fp", 2) == 0) || 
     (strncmp(drvlimit, "mpt", 3) == 0) ||
     (strncmp(drvlimit, "mpt_sas", 7) == 0) ||
     (strncmp(drvlimit, "pmcs", 4) == 0)))

Of course this one is a bit annoying to read, so we would like to reduce the !:

if (!(strncmp(drvlimit, "fp", 2) == 0) &&
    !(strncmp(drvlimit, "mpt", 3) == 0) &&
    !(strncmp(drvlimit, "mpt_sas", 7) == 0) &&
    !(strncmp(drvlimit, "pmcs", 4) == 0))

And from above we already can see why the error did appear, nevertheless, to remove negation at all, the final if statement should be:

if ((strncmp(drvlimit, "fp", 2) != 0) &&
    (strncmp(drvlimit, "mpt", 3) != 0) &&
    (strncmp(drvlimit, "mpt_sas", 7) != 0) &&
    (strncmp(drvlimit, "pmcs", 4) != 0))

Testing done:

Accepted, legal arguments:
# /tmp/stmsboot_util -D fp -L
stmsboot: MPXIO disabled

Bad arguments:
# /tmp/stmsboot_util -D fps -L
usage: stmsboot_util -b | -m devname | -l <ctrl> | -L | [-g] | -n | -N | -i | -p devname

More bad arguments:
# /tmp/stmsboot_util -D asd -L
usage: stmsboot_util -b | -m devname | -l <ctrl> | -L | [-g] | -n | -N | -i | -p devname