misc: chore: Use explicit types in CPU project

src/Ryujinx.Cpu/AppleHv/HvMemoryBlockAllocator.cs

@@ -45,7 +45,7 @@ namespace Ryujinx.Cpu.AppleHv
 
         public HvMemoryBlockAllocation Allocate(ulong size, ulong alignment)
         {
-            var allocation = Allocate(size, alignment, CreateBlock);
+            Allocation allocation = Allocate(size, alignment, CreateBlock);
 
             return new HvMemoryBlockAllocation(this, allocation.Block, allocation.Offset, allocation.Size);
         }