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

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>