esp.c: update end of transfer logic at the end of esp_transfer_data()

Since esp_dma_done() is called in both cases, and ti_size cannot be zero
(otherwise esp_command_complete() would have been called instead), replace
the conditional logic with a single call to esp_dma_done().

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Helge Deller <deller@gmx.de>
Tested-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20240112125420.514425-28-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

hw/scsi/esp.c

@@ -925,16 +925,10 @@ void esp_transfer_data(SCSIRequest *req, uint32_t len)
      */
 
     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
-        if (dmalen) {
-            esp_do_dma(s);
-        } else if (s->ti_size <= 0) {
-            /*
-             * If this was the last part of a DMA transfer then the
-             * completion interrupt is deferred to here.
-             */
-            esp_dma_done(s);
-            esp_lower_drq(s);
-        }
+        /* When the SCSI layer returns more data, raise deferred INTR_BS */
+        esp_dma_done(s);
+
+        esp_do_dma(s);
     } else if (s->ti_cmd == CMD_TI) {
         esp_do_nodma(s);
     }