[LEDE-DEV] fstools fixes backport to lede-17.01

[Daniel Golle]

Hi!

I'm about to push a lede-17.01 branch for fstools. These are the
changes I'd pick from the master branch:

f038a61 libfstools: fix matching device name
c43ae11 fstools: use -Wno-format-truncation instead of -Wno-error=format-truncation
633a8d0 libfstools: fix multiple volume_identify usages with the same volume
a19f2b3 build: disable the format-truncation warning error to fix gcc 7 build errors
88d48d5 libfstools: silence mkfs.{ext4,f2fs}
92b4c2c libfstools: add basic documentation of mount functions
7d78836 add missing includes


I'd skip the new mountd/autofs support which was added after the 17.01
release:

20c16fc cmake: Make blockd link against libjson-c
98bbb5a blockd: add automounting support

Please comment within the next 7 days, silence will be taken as passive
agreement.


Cheers


Daniel