mkfs: hook up suboption parsing to ini files

mkfs: hook up suboption parsing to ini files

Now we have the config file parsing hooked up and feeding in
parameters to mkfs, wire the parameters up to the existing CLI
option parsing functions. THis gives the config file exactly the
same capabilities and constraints as the command line option
specification.

[sandeen: fix whitespace, drop "opt" check in parse_subopts()]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>