new helper: uaccess_kernel()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index 6bd1089..9b4ed17 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -90,7 +90,7 @@
 	unsigned long ua_flags;
 	int atomic;
 
-	if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
+	if (uaccess_kernel()) {
 		memcpy((void *)to, from, n);
 		return 0;
 	}
@@ -162,7 +162,7 @@
 {
 	unsigned long ua_flags;
 
-	if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
+	if (uaccess_kernel()) {
 		memset((void *)addr, 0, n);
 		return 0;
 	}