Kernel: Access Processor static methods statically

SonarCloud flagged this "Code Smell", where we are accessing these
static methods as if they are instance methods. While it is technically
possible, it is very confusing to read when you realize they are static
functions.

Kernel/Heap/kmalloc.cpp

@@ -87,7 +87,7 @@ struct KmallocGlobalHeap {
                 // heap expansion may have been triggered while holding some
                 // other spinlock. If the expansion happens to need the same
                 // spinlock we would deadlock. So, if we're in any lock, defer
-                Processor::current().deferred_call_queue(kmalloc_allocate_backup_memory);
+                Processor::deferred_call_queue(kmalloc_allocate_backup_memory);
             });
 
             // Now that we added our backup memory, check if the backup heap