uuid.c: split uuid stuffs from util.c

uuid.c: split uuid stuffs from util.c

Currently, 'make raid6check' is build broken since commit b06815989
("mdadm: load default sysfs attributes after assemblation").

/usr/bin/ld: sysfs.o: in function `sysfsline':
sysfs.c:(.text+0x2707): undefined reference to `parse_uuid'
/usr/bin/ld: sysfs.c:(.text+0x271a): undefined reference to `uuid_zero'
/usr/bin/ld: sysfs.c:(.text+0x2721): undefined reference to `uuid_zero'

Apparently, the compile of mdadm or raid6check are coupled with uuid
functions inside util.c. However, we can't just add util.o to CHECK_OBJS
which raid6check is needed, because it caused other worse problems.

So, let's introduce a uuid.c file which is indenpended file to fix the
problem, all the contents are splitted from util.c.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>