Omit a redundant error check if sizeof(HashtableItem) > 10

`sizeof(HashtableItem)` should be always > 10 for all platforms htop
currently supports (32-bit or 64-bit).
If `Hashtable.size > SIZE_MAX / sizeof(HashtableItem)`, the buffer
allocation would fail at xCalloc(), and a conditional for checking `size` overflow would be redundant.

Signed-off-by: Kang-Che Sung <explorer09@gmail.com>

Author: Explorer09

Hashtable.c

@@ -224,11 +224,12 @@ void Hashtable_put(Hashtable* this, ht_key_t key, void* value) {
 
    assert(Hashtable_isConsistent(this));
    assert(this->size > 0);
+   assert(this->size <= SIZE_MAX / sizeof(HashtableItem));
    assert(value);
 
    /* grow on load-factor > 0.7 */
    if (10 * this->items > 7 * this->size) {
-      if (SIZE_MAX / 2 < this->size)
+      if (sizeof(HashtableItem) < 10 && SIZE_MAX / 10 < this->size)
          CRT_fatalError("Hashtable: size overflow");
 
       Hashtable_setSize(this, 2 * this->size);