Clean up tests and do runtime test for max name length

- Remove unused code
- Use standard functions declared in common.c
- Change tests to do a runtime test for the max name length of a path
  component (aka NAME_MAX). The actual value might differ from the hard
  coded NAME_MAX depending on the file system used.

test/common.c

@@ -15,6 +15,7 @@ int common_test_nr = -1, errct = 0, subtest;
 _PROTOTYPE(void cleanup, (void));
 _PROTOTYPE(int does_fs_truncate, (void));
 _PROTOTYPE(void e, (int n));
+_PROTOTYPE(int name_max, (char *path));
 _PROTOTYPE(void quit, (void));
 _PROTOTYPE(void rm_rf_dir, (int test_nr));
 _PROTOTYPE(void rm_rf_ppdir, (int test_nr));
@@ -59,6 +60,14 @@ int does_fs_truncate(void)
   return(does_truncate); 
 }
 
+int name_max(char *path)
+{
+  struct statvfs stvfs;
+
+  if (statvfs(path, &stvfs) != 0) e(7779);
+  return(stvfs.f_namemax);
+}
+
 
 void rm_rf_dir(test_nr)
 int test_nr;