Fix for a typo in comment: "read read" -> "read"

I just did add an small nit, see https://www.illumos.org/rb/r/403/diff/2-3/ just to be sure we wont get partial reads (which may happen with IO errors).

What is the current status of this work?

fixed these two style issues

Added overflow prevention to fatget() function, submitted whole file diff.

I've read this comment:
https://www.illumos.org/rb/r/403/#comment1770

Freeing of DOS_FS structure was moved from dos_mount() to dos_open(), where allocation happens. Also error handling in dos_open() was improved, resource leaks fixed.

indentation fixed at line 165

cstyle issues were fixed.

I have tested this patch in my environment and confirm that it works as expected (fixes PR214423).