Some issues reported by Coverity Scan about libdatrie HOT 1 OPEN

> 1. Defect type: GCC_ANALYZER_WARNING
> 1. libdatrie-0.2.13/datrie/trie.c:1115:14: warning[-Wanalyzer-malloc-leak]: leak of 's'
> 41. libdatrie-0.2.13/datrie/trie.c:75:62: note: in definition of macro 'trie_da_get_tail_index'
> #  1113|           *alpha_p++ = alpha_map_trie_to_char (s->trie->alpha_map, *tail_str++);
> #  1114|       }
> #  1115|->     *alpha_p = 0;
> #  1116|   
> #  1117|       return alpha_key;

> 2. Defect type: GCC_ANALYZER_WARNING
> 1. libdatrie-0.2.13/datrie/trie-string.c:64:8: warning[-Wanalyzer-possible-null-dereference]: dereference of possibly-NULL 'p'
> #    62|           *p++ = *str++;
> #    63|       }
> #    64|->     *p = TRIE_CHAR_TERM;
> #    65|   
> #    66|       return dup;