Kyle Evans c3e9752ea1 fsck_ffs/fsdb: fix -fno-common build ...

This one is also a small list:

- 3x duplicate definition (ufs2_zino, returntosingle, nflag)
- 5x 'needs extern', 3/5 of which are referenced in fsdb

-fno-common will become the default in GCC10/LLVM11.

MFC after:	1 week

2020-03-29 20:03:46 +00:00

..

fsdb.8

…

fsdb.c

…

fsdb.h

…

fsdbutil.c

…

Makefile

…

Makefile.depend

…