LaxConnPool: Loop over expired connections

This change brings `LaxConnPool` into alignment with `StrictConnPool`,
which loops over pool entries and discards expired ones as they are
discovered, instead of returning them.

Author: rschmitt

httpcore5/src/main/java/org/apache/hc/core5/pool/LaxConnPool.java

@@ -442,13 +442,11 @@ private PoolEntry<T, C> getAvailableEntry(final Object state) {
                 final PoolEntry<T, C> entry = ref.getReference();
                 if (ref.compareAndSet(entry, entry, false, true)) {
                     it.remove();
-                    if (entry.getExpiryDeadline().isExpired()) {
+                    if (entry.getExpiryDeadline().isExpired() || !Objects.equals(entry.getState(), state)) {
                         entry.discardConnection(CloseMode.GRACEFUL);
+                    } else {
+                        return entry;
                     }
-                    if (!Objects.equals(entry.getState(), state)) {
-                        entry.discardConnection(CloseMode.GRACEFUL);
-                    }
-                    return entry;
                 }
             }
             return null;