gpio: break the while loop to avoid test failure

The "test_gpio_process_events_multi_success" test currently hangs with
an update to a newer version of Rust. The code here tries to read the
value, locked, for each GPIO one by one. The values are updated in
another thread with the help of write lock.

More discussion around this issue can be found here.

rust-lang/rust#101194

Breaking the while loop into three, one for each GPIO fixes it for now.
This is the simplest solution possible right now.

Signed-off-by: Viresh Kumar <[email protected]>

Author: vireshk

gpio/src/vhu_gpio.rs

@@ -929,10 +929,9 @@ mod tests {
 
         backend.process_events(desc_chains.clone(), &vring).unwrap();
 
-        while backend.handles.read().unwrap()[GPIO as usize].is_some()
-            || backend.handles.read().unwrap()[(GPIO + 1) as usize].is_some()
-            || backend.handles.read().unwrap()[(GPIO + 2) as usize].is_some()
-        {}
+        while backend.handles.read().unwrap()[GPIO as usize].is_some() {}
+        while backend.handles.read().unwrap()[(GPIO + 1) as usize].is_some() {}
+        while backend.handles.read().unwrap()[(GPIO + 2) as usize].is_some() {}
 
         validate_desc_chains(desc_chains, VIRTIO_GPIO_IRQ_STATUS_VALID, None);
     }