[Bug-tar] gtar-1.15.1 build fails (strdup) on old system

[Bernhard Simon]

There are some "strdup" left in src/create.c, src/names.c, and src/tar.c.
The following changes will make ULTRIX V4.5 happy:

# diff src/create.c.ORIG src/create.c
1069c1069
<     char *name_buf = strdup (st->orig_file_name);
---
>     char *name_buf = xstrdup (st->orig_file_name);

# diff src/names.c.ORIG src/names.c
69c69
<       *uname = strdup ("");
---
>       *uname = xstrdup ("");
84c84
<         *uname = strdup ("");
---
>         *uname = xstrdup ("");
88c88
<   *uname = strdup (cached_uname);
---
>   *uname = xstrdup (cached_uname);
99c99
<       *gname = strdup ("");
---
>       *gname = xstrdup ("");
114c114
<         *gname = strdup ("");
---
>         *gname = xstrdup ("");
118c118
<   *gname = strdup (cached_gname);
---
>   *gname = xstrdup (cached_gname);

# diff src/tar.c.ORIG src/tar.c
1234c1234
<       archive_name_array[archive_names++] = strdup (buf);
---
>       archive_name_array[archive_names++] = xstrdup (buf);

Regards - bernhard