x86/mm: Remove unused current_untag_mask()

e0bddc1 ("x86/mm: Reduce untagged_addr() overhead for systems without LAM")

removed its only usage site so drop it.

Move the tlbstate_untag_mask up in the header and drop the ugly
ifdeffery as the unused declaration should be properly discarded.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20230614174148.5439-1-bp@alien8.de

Author: bp3tk0v

arch/x86/include/asm/tlbflush.h

@@ -14,6 +14,8 @@
 #include <asm/processor-flags.h>
 #include <asm/pgtable.h>
 
+DECLARE_PER_CPU(u64, tlbstate_untag_mask);
+
 void __flush_tlb_all(void);
 
 #define TLB_FLUSH_ALL	-1UL
@@ -54,15 +56,6 @@ static inline void cr4_clear_bits(unsigned long mask)
 	local_irq_restore(flags);
 }
 
-#ifdef CONFIG_ADDRESS_MASKING
-DECLARE_PER_CPU(u64, tlbstate_untag_mask);
-
-static inline u64 current_untag_mask(void)
-{
-	return this_cpu_read(tlbstate_untag_mask);
-}
-#endif
-
 #ifndef MODULE
 /*
  * 6 because 6 should be plenty and struct tlb_state will fit in two cache