Use the new scheme format in most places

The graphics subsystem still uses the old format as orbital manually
parses the fpath result.

audio/ihdad/src/main.rs

@@ -113,7 +113,7 @@ fn get_int_method(pcid_handle: &mut PciFunctionHandle) -> File {
         log::debug!("Legacy IRQ {}", irq);
 
         // legacy INTx# interrupt pins.
-        File::open(format!("irq:{}", irq)).expect("ihdad: failed to open legacy IRQ file")
+        irq.irq_handle("ihdad")
     } else {
         panic!("ihdad: no interrupts supported at all")
     }
@@ -126,7 +126,7 @@ fn get_int_method(pcid_handle: &mut PciFunctionHandle) -> File {
 
     if let Some(irq) = pci_config.func.legacy_interrupt_line {
         // legacy INTx# interrupt pins.
-        File::open(format!("irq:{}", irq)).expect("ihdad: failed to open legacy IRQ file")
+        irq.irq_handle("ihdad")
     } else {
         panic!("ihdad: no interrupts supported at all")
     }

audio/sb16d/src/main.rs

@@ -73,7 +73,7 @@ fn main() {
 
         //TODO: error on multiple IRQs?
         let irq_file = match device.irqs.first() {
-            Some(irq) => Fd::open(&format!("irq:{}", irq), flag::O_RDWR, 0).expect("sb16d: failed to open IRQ file"),
+            Some(irq) => Fd::open(&format!("/scheme/irq/{}", irq), flag::O_RDWR, 0).expect("sb16d: failed to open IRQ file"),
             None => panic!("sb16d: no IRQs found"),
         };
         user_data! {