kasan: remove redundant initialization of variable 'real_size'

Variable real_size is initialized with a value that is never read, it is
re-assigned a new value later on, hence the initialization is redundant
and can be removed.

Cleans up clang warning:

  lib/test_kasan.c:422:21: warning: Value stored to 'real_size' during its initialization is never read

Link: http://lkml.kernel.org/r/20180206144950.32457-1-colin.king@canonical.comSigned-off-by: NColin Ian King <colin.king@canonical.com>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/test_kasan.c

@@ -419,7 +419,7 @@ static noinline void __init kasan_stack_oob(void)
 static noinline void __init ksize_unpoisons_memory(void)
 {
 	char *ptr;
-	size_t size = 123, real_size = size;
+	size_t size = 123, real_size;
 
 	pr_info("ksize() unpoisons the whole allocated chunk\n");
 	ptr = kmalloc(size, GFP_KERNEL);