Revert "simple fix. Socket read return -1 for error."

Ruby 3.3 changes recv(0) to nil and 9.4 is 3.1.

This reverts commit 5a8ab05.

core/src/main/java/org/jruby/ext/socket/RubyBasicSocket.java

@@ -238,9 +238,9 @@ private IRubyObject recv(ThreadContext context, IRubyObject length,
                 return null; // not reached
             }
         } else {
-            bytes = doRead(context, buffer);
-            if (bytes == null) return context.nil;
+                bytes = doRead(context, buffer);
         }
+        if (bytes == null) return context.nil;
 
         if (str != null) {
             str.setValue(bytes);
@@ -738,7 +738,8 @@ protected ByteList doRead(ThreadContext context, final ByteBuffer buffer) {
             context.getThread().beforeBlockingCall(context);
 
             int read = openFile.readChannel().read(buffer);
-            if (read <= 0) return null;
+
+            if (read == 0) return null;
 
             return new ByteList(buffer.array(), 0, buffer.position(), false);
         } catch (Exception e) {