uml: const and other tidying

This patch also does some improvements for uml code.  Improvements include
dropping unnecessary cast, killing some unnecessary code and still some
constifying for pointers etc..

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index e3e7241..96072e2 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -65,7 +65,7 @@
 void __init mem_init(void)
 {
 	/* clear the zero-page */
-	memset((void *) empty_zero_page, 0, PAGE_SIZE);
+	memset(empty_zero_page, 0, PAGE_SIZE);
 
 	/* Map in the area just after the brk now that kmalloc is about
 	 * to be turned on.
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index c7ea7f2..91bd68e 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -60,8 +60,6 @@
 	if (atomic)
 		flags = GFP_ATOMIC;
 	page = __get_free_pages(flags, order);
-	if (page == 0)
-		return 0;
 
 	return page;
 }
@@ -331,7 +329,7 @@
 		(*call)();
 }
 
-char *uml_strdup(char *string)
+char *uml_strdup(const char *string)
 {
 	return kstrdup(string, GFP_KERNEL);
 }