malloc: fix realloc padded element size

When resize a memory with next element, the original element size grows.
If the orginal element has padding, the real inner element size didn't
grow as well and this causes trailer verification failure when malloc
debug enabled.

Fixes: af75078 ("first public release")
Cc: stable@dpdk.org

Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>

lib/librte_eal/common/malloc_elem.c

@@ -307,6 +307,11 @@ split_elem(struct malloc_elem *elem, struct malloc_elem *split_pt)
 	elem->next = split_pt;
 	elem->size = old_elem_size;
 	set_trailer(elem);
+	if (elem->pad) {
+		/* Update inner padding inner element size. */
+		elem = RTE_PTR_ADD(elem, elem->pad);
+		elem->size = old_elem_size - elem->pad;
+	}
 }
 
 /*