Kernel/Storage: Rename the method hba_region => default_hba_region

Also, make sure we unmap it after the init process.

Kernel/Storage/AHCIController.cpp

@@ -82,7 +82,7 @@ volatile AHCI::HBA& AHCIController::hba() const
 AHCIController::AHCIController(PCI::Address address)
     : StorageController()
     , PCI::DeviceController(address)
-    , m_hba_region(hba_region())
+    , m_hba_region(default_hba_region())
     , m_capabilities(capabilities())
 {
     initialize();
@@ -125,7 +125,7 @@ AHCI::HBADefinedCapabilities AHCIController::capabilities() const
     };
 }
 
-NonnullOwnPtr<Region> AHCIController::hba_region() const
+NonnullOwnPtr<Region> AHCIController::default_hba_region() const
 {
     auto region = MM.allocate_kernel_region(PhysicalAddress(PCI::get_BAR5(pci_address())).page_base(), page_round_up(sizeof(AHCI::HBA)), "AHCI HBA", Region::Access::Read | Region::Access::Write);
     return region.release_nonnull();

Kernel/Storage/AHCIController.h

@@ -48,7 +48,7 @@ private:
     RefPtr<StorageDevice> device_by_port(u32 index) const;
 
     volatile AHCI::PortRegisters& port(size_t port_number) const;
-    NonnullOwnPtr<Region> hba_region() const;
+    UNMAP_AFTER_INIT NonnullOwnPtr<Region> default_hba_region() const;
     volatile AHCI::HBA& hba() const;
 
     NonnullOwnPtr<Region> m_hba_region;