scsi: jazz_esp: Add IRQ check

The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to request_irq() (which takes
*unsigned* IRQ #), causing it to fail with -EINVAL, overriding the real
error code. Stop calling request_irq() with the invalid IRQ #s.

Link: https://lore.kernel.org/r/[e-mail]
Fixes: 352e921f0dd4 ("[SCSI] jazz_esp: converted to use esp_core")
Signed-off-by: Sergey Shtylyov <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/jazz_esp.c

···
 	if (!esp->command_block)
 		goto fail_unmap_regs;
 
-	host->irq = platform_get_irq(dev, 0);
+	host->irq = err = platform_get_irq(dev, 0);
+	if (err < 0)
+		goto fail_unmap_command_block;
 	err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED, "ESP", esp);
 	if (err < 0)
 		goto fail_unmap_command_block;