[PATCH] malloc: Fix tst bug in malloc/tst-free-errno-malloc-hugetlb1.

[caiyinyu]

When transparent hugepages (THP) are configured to 32MB on x86/loongarch
systems, the current big_size value may not be sufficiently large to
guarantee that free(ptr) [1] will call munmap(ptr_aligned, big_size).

Tested on x86_64 and loongarch64.

PS: Without this patch and using 32M THP, there is a about 50% chance
that malloc/tst-free-errno-malloc-hugetlb1 will fail on both x86_64 and
loongarch64.

[1] malloc/tst-free-errno.c:
...
       errno = 1789;
       /* This call to free() is supposed to call
            munmap (ptr_aligned, big_size);
          which increases the number of VMAs by 1, which is supposed
          to fail.  */
->     free (ptr);
       TEST_VERIFY (get_errno () == 1789);
     }
...
---
 malloc/tst-free-errno.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/malloc/tst-free-errno.c b/malloc/tst-free-errno.c
index 0e7a0f2b71..1c50860e7e 100644
--- a/malloc/tst-free-errno.c
+++ b/malloc/tst-free-errno.c
@@ -88,7 +88,7 @@ do_test (void)
 	FAIL_EXIT1 ("cannot create temporary file");
 
       /* Do a large memory allocation.  */
-      size_t big_size = 0x1000000;
+      size_t big_size = 0x3000000;
       void * volatile ptr = xmalloc (big_size - 0x100);
       char *ptr_aligned = (char *) ((uintptr_t) ptr & ~(pagesize - 1));
       /* This large memory allocation allocated a memory area
-- 
2.45.2