arm64/mm: fix variable 'pud' set but not used

GCC throws a warning,

arch/arm64/mm/mmu.c: In function 'pud_free_pmd_page':
arch/arm64/mm/mmu.c:1033:8: warning: variable 'pud' set but not used
[-Wunused-but-set-variable]
  pud_t pud;
        ^~~

because pud_table() is a macro and compiled away. Fix it by making it a
static inline function and for pud_sect() as well.
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/pgtable.h

@@ -447,8 +447,8 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 				 PMD_TYPE_SECT)
 
 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
-#define pud_sect(pud)		(0)
-#define pud_table(pud)		(1)
+static inline bool pud_sect(pud_t pud) { return false; }
+static inline bool pud_table(pud_t pud) { return true; }
 #else
 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
 				 PUD_TYPE_SECT)