EDAC/dmc520: Don't print an error for each unconfigured interrupt line

The dmc520 driver requires that at least one interrupt line, out of the
ten possible, is configured. The driver prints an error and returns
-EINVAL from its .probe function if there are no interrupt lines
configured.

Don't print a KERN_ERR level message for each interrupt line that's
unconfigured as that can confuse users into thinking that there is an
error condition.

Before this change, the following KERN_ERR level messages would be
reported if only dram_ecc_errc and dram_ecc_errd were configured in the
device tree:

  dmc520 68000000.dmc: IRQ ram_ecc_errc not found
  dmc520 68000000.dmc: IRQ ram_ecc_errd not found
  dmc520 68000000.dmc: IRQ failed_access not found
  dmc520 68000000.dmc: IRQ failed_prog not found
  dmc520 68000000.dmc: IRQ link_err not
  dmc520 68000000.dmc: IRQ temperature_event not found
  dmc520 68000000.dmc: IRQ arch_fsm not found
  dmc520 68000000.dmc: IRQ phy_request not found

Fixes: 1088750d ("EDAC: Add EDAC driver for DMC520")
Reported-by: NSinan Kaya <okaya@kernel.org>
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220111163800.22362-1-tyhicks@linux.microsoft.com

drivers/edac/dmc520_edac.c

@@ -489,7 +489,7 @@ static int dmc520_edac_probe(struct platform_device *pdev)
 	dev = &pdev->dev;
 
 	for (idx = 0; idx < NUMBER_OF_IRQS; idx++) {
-		irq = platform_get_irq_byname(pdev, dmc520_irq_configs[idx].name);
+		irq = platform_get_irq_byname_optional(pdev, dmc520_irq_configs[idx].name);
 		irqs[idx] = irq;
 		masks[idx] = dmc520_irq_configs[idx].mask;
 		if (irq >= 0) {