Quash stat(2) st_rdev unless we're going to need it for mknod().

Quash stat(2) st_rdev unless we're going to need it for mknod().

On some platforms (i.e. kFreeBSD), the st_rdev value isn't completely
stable.  For example, given "date > foo; cp -a foo foo-2", the st_rdev
value may differ between the two files.

Since we only need the st_rdev value for the call to mknod() when
restoring character and block special files, set it to zero for
anything else.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>