uss: Fix IP address parsing and cleanup warnings

uss: Fix IP address parsing and cleanup warnings

In uss_vol_GetServer(), the IP address octets are scanned into "char"
variables, and later cast to afs_int32 to build the address.
sscanf gives warnings because it's expecting an int pointer, and
testing shows that this code doesn't work as expected - the first
3 octets are always parsed as 0.

Use afs_int32 variables instead, which works, eliminates warnings and
simplifies the code.

Note that this code does not seem to be reachable currently.
It was probably meant to be used by planned additional uss commands.

Change-Id: I646d4cbfa8ac0d0c50f98a334ac3fe387d6d361b
Reviewed-on: http://gerrit.openafs.org/1119
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>