tar -L broken in tar 1.13

[Martin Guy]

Hi!
   From 1.12 to 1.13 someone broke the -L flag (change media every
N*1024 bytes).
In src/tar.c search for the 2nd occurrence of 'L' and you'll find that
the strtoul test has changed into xstrtoul with a test that always fails
on any legal value. I guess it should test against LONGINT_OK.
There's another occurrence of this boob elsewhere in the file - search
for LONG_MAX.

All the best

    Martin