Impact: cleanup
This compiler warning:
  arch/x86/mm/init_32.c:515: warning: unused variable 'pgd_base'
triggers because permanent_kmaps_init() is a CPP macro in the
!CONFIG_HIGHMEM case, that does not tell the compiler that the
'pgd_base' parameter is used.
Convert permanent_kmaps_init() (and set_highmem_pages_init()) to
C inline functions - which gives the parameter a proper type and
which gets rid of the compiler warning as well.
Signed-off-by: Ingo Brueckl <ib@wupperonline.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
 #endif /* !CONFIG_NUMA */
 
 #else
-# define permanent_kmaps_init(pgd_base)                do { } while (0)
-# define set_highmem_pages_init()      do { } while (0)
+static inline void permanent_kmaps_init(pgd_t *pgd_base)
+{
+}
+static inline void set_highmem_pages_init(void)
+{
+}
 #endif /* CONFIG_HIGHMEM */
 
 void __init native_pagetable_setup_start(pgd_t *base)