[bug report] ubifs: Fix unlink code wrt. double hash lookups

[Dan Carpenter]

Hello Richard Weinberger,

The patch 781f675e2d7e: "ubifs: Fix unlink code wrt. double hash
lookups" from May 17, 2017, leads to the following static checker
warning:

	fs/ubifs/tnc.c:1893 search_dh_cookie()
	error: uninitialized symbol 'err'.

fs/ubifs/tnc.c
  1883  static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key,
  1884                              struct ubifs_dent_node *dent, uint32_t cookie,
  1885                              struct ubifs_znode **zn, int *n)
  1886  {
  1887          int err;
                ^^^^^^^

This used to be initialized with:

	err = ubifs_lookup_level0(c, &start_key, &znode, &n);

  1888          struct ubifs_znode *znode = *zn;
  1889          struct ubifs_zbranch *zbr;
  1890          union ubifs_key *dkey;
  1891  
  1892          for (;;) {
  1893                  if (!err) {
                            ^^^^
Uninitialized.

  1894                          err = tnc_next(c, &znode, n);
  1895                          if (err)
  1896                                  goto out;
  1897                  }
  1898  
  1899                  zbr = &znode->zbranch[*n];
  1900                  dkey = &zbr->key;
  1901  
  1902                  if (key_inum(c, dkey) != key_inum(c, key) ||
  1903                      key_type(c, dkey) != key_type(c, key)) {
  1904                          err = -ENOENT;
  1905                          goto out;
  1906                  }
  1907  
  1908                  err = tnc_read_hashed_node(c, zbr, dent);
  1909                  if (err)
  1910                          goto out;
  1911  
  1912                  if (key_hash(c, key) == key_hash(c, dkey) &&
  1913                      le32_to_cpu(dent->cookie) == cookie) {
  1914                          *zn = znode;
  1915                          goto out;
  1916                  }
  1917          }
  1918  
  1919  out:
  1920  
  1921          return err;
  1922  }

regards,
dan carpenter