xhcid: panic if BAR is 0

xhcid/src/main.rs

@@ -101,7 +101,10 @@ fn main() {
     name.push_str("_xhci");
 
     let bar_ptr = match bar {
-        pcid_interface::PciBar::Memory(ptr) => ptr,
+        pcid_interface::PciBar::Memory(ptr) => match ptr {
+            0 => panic!("BAR is mapped to address 0"),
+            _ => ptr,
+        },
         other => panic!("Expected memory bar, found {}", other),
     };