misc: Remove manual implementation of is_power_of_two

As clippy of rust-toolchain version 1.83.0-beta.1 suggests, remove
manual implementation of `is_power_of_two` to improve readability.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

block/src/qcow/qcow_raw_file.rs

@@ -24,7 +24,7 @@ impl QcowRawFile {
     /// Creates a `QcowRawFile` from the given `File`, `None` is returned if `cluster_size` is not
     /// a power of two.
     pub fn from(file: RawFile, cluster_size: u64) -> Option<Self> {
-        if cluster_size.count_ones() != 1 {
+        if !cluster_size.is_power_of_two() {
             return None;
         }
         Some(QcowRawFile {

pci/src/configuration.rs

@@ -734,7 +734,7 @@ impl PciConfiguration {
             return Err(Error::BarInUse(bar_idx));
         }
 
-        if config.size.count_ones() != 1 {
+        if !config.size.is_power_of_two() {
             return Err(Error::BarSizeInvalid(config.size));
         }
 
@@ -806,7 +806,7 @@ impl PciConfiguration {
             return Err(Error::RomBarInUse(bar_idx));
         }
 
-        if config.size.count_ones() != 1 {
+        if !config.size.is_power_of_two() {
             return Err(Error::RomBarSizeInvalid(config.size));
         }
 

vm-virtio/src/queue.rs

@@ -178,7 +178,7 @@ pub mod testing {
         // We try to make sure things are aligned properly :-s
         pub fn new(start: GuestAddress, mem: &'a GuestMemoryMmap, qsize: u16) -> Self {
             // power of 2?
-            assert!(qsize > 0 && qsize & (qsize - 1) == 0);
+            assert!(qsize.is_power_of_two());
 
             let mut dtable = Vec::with_capacity(qsize as usize);