If 64-bit mask attempt fails, the 32-bit will fail by the very same reason.
Don't even try the latter. It's a continuation of the changes that contains,
e.g. dcc02c19cc06 ("sata_sil24: use dma_set_mask_and_coherent").

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/ata/libahci_platform.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index 1af642c84e7b..972f5ec86a27 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c

@@ -637,13 +637,8 @@ int ahci_platform_init_host(struct platform_device *pdev,
 	if (hpriv->cap & HOST_CAP_64) {
 		rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
 		if (rc) {
-			rc = dma_coerce_mask_and_coherent(dev,
-							  DMA_BIT_MASK(32));
-			if (rc) {
-				dev_err(dev, "Failed to enable 64-bit DMA.\n");
-				return rc;
-			}
-			dev_warn(dev, "Enable 32-bit DMA instead of 64-bit.\n");
+			dev_err(dev, "Failed to enable 64-bit DMA.\n");
+			return rc;
 		}
 	}