bug#79328: expr: memory not freed before program exit(memory leak)

Package: coreutils
Version: 9.4
Severity: normal

I was trying to build coreutils with ASan, and found a memory leak in expr.

When running:
 expr length "hello"

Output:
=================================================================
==755058==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0xffff7f7a2524 in __interceptor_malloc
../../../../libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0xaaaacd31f4c8 in xmalloc ../lib/xmalloc.c:45
    #2 0xaaaacd2a0dd4 in int_value ../src/expr.c:369
    #3 0xaaaacd2a0dd4 in eval6 ../src/expr.c:714
    #4 0xaaaacd2a0dd4 in eval6 ../src/expr.c:694
    #5 0xaaaacd2a4f44 in eval5 ../src/expr.c:786
    #6 0xaaaacd2a5320 in eval4 ../src/expr.c:817
    #7 0xaaaacd2a595c in eval3 ../src/expr.c:856
    #8 0xaaaacd2a5dbc in eval2 ../src/expr.c:886
    #9 0xaaaacd2a72e0 in eval1 ../src/expr.c:965
    #10 0xaaaacd2a7874 in eval ../src/expr.c:996
    #11 0xaaaacd29d3e0 in main ../src/expr.c:352