sh: Prefer slab_is_available() over after_bootmem.

This kills off after_bootmem and switches to using slab_is_available()
instead. Presently the only place this is used is by the sh64 ioremap,
and there's not much point in keeping the reference around otherwise.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/mm/init.c

@@ -184,7 +184,6 @@ void __init paging_init(void)
 }
 
 static struct kcore_list kcore_mem, kcore_vmalloc;
-int after_bootmem = 0;
 
 void __init mem_init(void)
 {
@@ -217,8 +216,6 @@ void __init mem_init(void)
 	memset(empty_zero_page, 0, PAGE_SIZE);
 	__flush_wback_region(empty_zero_page, PAGE_SIZE);
 
-	after_bootmem = 1;
-
 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;

arch/sh/mm/ioremap_64.c

@@ -20,6 +20,7 @@
 #include <linux/io.h>
 #include <linux/bootmem.h>
 #include <linux/proc_fs.h>
+#include <linux/slab.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
 #include <asm/addrspace.h>
@@ -175,7 +176,7 @@ static __init_refok void *sh64_get_page(void)
 {
 	void *page;
 
-	if (after_bootmem)
+	if (slab_is_available())
 		page = (void *)get_zeroed_page(GFP_KERNEL);
 	else
 		page = alloc_bootmem_pages(PAGE_SIZE);