Kernel: Use range-for wherever possible

Kernel/Bus/PCI/Definitions.h

@@ -198,7 +198,7 @@ public:
         , m_capabilities(capabilities)
     {
         if constexpr (PCI_DEBUG) {
-            for (auto capability : capabilities)
+            for (const auto& capability : capabilities)
                 dbgln("{} has capability {}", address, capability.id());
         }
     }

Kernel/Bus/PCI/DeviceController.cpp

@@ -16,7 +16,7 @@ DeviceController::DeviceController(Address address)
 
 bool DeviceController::is_msi_capable() const
 {
-    for (auto capability : PCI::get_physical_id(pci_address()).capabilities()) {
+    for (const auto& capability : PCI::get_physical_id(pci_address()).capabilities()) {
         if (capability.id() == PCI_CAPABILITY_MSI)
             return true;
     }
@@ -24,7 +24,7 @@ bool DeviceController::is_msi_capable() const
 }
 bool DeviceController::is_msix_capable() const
 {
-    for (auto capability : PCI::get_physical_id(pci_address()).capabilities()) {
+    for (const auto& capability : PCI::get_physical_id(pci_address()).capabilities()) {
         if (capability.id() == PCI_CAPABILITY_MSIX)
             return true;
     }

Kernel/Graphics/VirtIOGPU/VirtIOGPU.h

@@ -185,8 +185,7 @@ public:
     template<typename F>
     IterationDecision for_each_framebuffer(F f)
     {
-        for (size_t i = 0; i < VIRTIO_GPU_MAX_SCANOUTS; i++) {
-            auto& scanout = m_scanouts[i];
+        for (auto& scanout : m_scanouts) {
             if (!scanout.framebuffer)
                 continue;
             IterationDecision decision = f(*scanout.framebuffer, *scanout.console);