CLEANUP: pools: remove the now unused pool_is_crowded()

This function was renderred obsolete by commit a0b5831ee ("MEDIUM: pools:
centralize cache eviction in a common function") which replaced its last
call inside the loop with a single call out of the loop to pool_releasable()
as introduced by commit 91a8e28f9 ("MINOR: pool: add a function to estimate
how many may be released at once"). Let's remove it before it becomes wrong
and used again.
diff --git a/include/haproxy/pool.h b/include/haproxy/pool.h
index 9aec880..9f8658d 100644
--- a/include/haproxy/pool.h
+++ b/include/haproxy/pool.h
@@ -144,12 +144,6 @@
 
 #if defined(CONFIG_HAP_NO_GLOBAL_POOLS)
 
-static inline int pool_is_crowded(const struct pool_head *pool)
-{
-	/* no shared pools, hence they're always full */
-	return 1;
-}
-
 static inline uint pool_releasable(const struct pool_head *pool)
 {
 	/* no room left */
@@ -171,13 +165,6 @@
 void pool_refill_local_from_shared(struct pool_head *pool, struct pool_cache_head *pch);
 void pool_put_to_shared_cache(struct pool_head *pool, struct pool_item *item, uint count);
 
-/* returns true if the pool is considered to have too many free objects */
-static inline int pool_is_crowded(const struct pool_head *pool)
-{
-	return pool->allocated >= swrate_avg(pool->needed_avg + pool->needed_avg / 4, POOL_AVG_SAMPLES) &&
-	       (int)(pool->allocated - pool->used) >= pool->minavail;
-}
-
 /* Returns the max number of entries that may be brought back to the pool
  * before it's considered as full. Note that it is only usable for releasing
  * objects, hence the function assumes that no more than ->used entries will