PCI: endpoint: Return -EINVAL when interrupts num is smaller than 1

In pci_epc_set_msi() we should return immediately if there are no
interrupts to configure; update the code to return early.

Link: https://lore.kernel.org/r/CH2PR19MB402491B9E503694DBCAC6005A07C9@CH2PR19MB4024.namprd19.prod.outlook.com
Signed-off-by: Li Chen <lchen@ambarella.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>

Author: FirstLoveLife

drivers/pci/endpoint/pci-epc-core.c

@@ -334,7 +334,7 @@ int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no, u8 interrupts)
 	u8 encode_int;
 
 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
-	    interrupts > 32)
+	    interrupts < 1 || interrupts > 32)
 		return -EINVAL;
 
 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))