Kernel: Avoid creating a temporary String("mmap") for every mmap() call

Kernel/Process.cpp

@@ -208,13 +208,11 @@ void* Process::sys$mmap(const Syscall::SC_mmap_params* params)
     if ((u32)addr & ~PAGE_MASK)
         return (void*)-EINVAL;
     if (flags & MAP_ANONYMOUS) {
-        auto* region = allocate_region(VirtualAddress((u32)addr), size, "mmap", prot, false);
+        auto* region = allocate_region(VirtualAddress((u32)addr), size, name ? name : "mmap", prot, false);
         if (!region)
             return (void*)-ENOMEM;
         if (flags & MAP_SHARED)
             region->set_shared(true);
-        if (name)
-            region->set_name(name);
         return region->vaddr().as_ptr();
     }
     if (offset & ~PAGE_MASK)