PCI: endpoint: pci-epf-vntb: Return -ENOENT if pci_epc_get_next_free_bar() fails

According the function documentation of epf_ntb_init_epc_bar(), the
function should return an error code on error. However, it returns -1 when
no BAR is available i.e., when pci_epc_get_next_free_bar() fails.

Return -ENOENT instead.

Fixes: e35f56b ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
[mani: changed err code to -ENOENT]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20250603-pci-vntb-bar-mapping-v2-1-fc685a22ad28@baylibre.com

Author: jbrun3t

drivers/pci/endpoint/functions/pci-epf-vntb.c

@@ -680,7 +680,7 @@ static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
 		barno = pci_epc_get_next_free_bar(epc_features, barno);
 		if (barno < 0) {
 			dev_err(dev, "Fail to get NTB function BAR\n");
-			return barno;
+			return -ENOENT;
 		}
 		ntb->epf_ntb_bar[bar] = barno;
 	}