Use fmt -w WIDTH option instead of -WIDTH

Use fmt -w WIDTH option instead of -WIDTH

Most systems support -WIDTH option which is an abbreviated form
of -w WIDTH or --width=WIDTH option, but some OS don't support
-WIDTH format.

As far as I've checked (on actual systems or online manpages),
Linux/FreeBSD/DragonFlyBSD/OpenBSD/Solaris/AIX/Cygwin support
-WIDTH format, but NetBSD doesn't support this (see below).
IRIX and HPUX may not support either according to online manpages.

-w WIDTH format is basically supported by all systems that have
fmt command, so this is probably better in terms of portability.

--
    CC crc/crc64.o
fmt: unknown option -- 1
Usage: fmt [-Cr] [-g <goal>] [-m|w <max>] [<files>..]
         fmt [-Cr] [<goal>] [<max>] [<files>]
    CC crc/md5.o
fmt: unknown option -- 1
Usage: fmt [-Cr] [-g <goal>] [-m|w <max>] [<files>..]
         fmt [-Cr] [<goal>] [<max>] [<files>]
...

Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>