zsmalloc: use U suffix for negative literals being shifted

Fix warning about shifting unsigned literals being undefined behavior.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Nick Desaulniers <[email protected]>
Suggested-by: Minchan Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: nickdesaulniers

mm/zsmalloc.c

@@ -1047,7 +1047,7 @@ static void init_zspage(struct size_class *class, struct zspage *zspage)
 			 * Reset OBJ_TAG_BITS bit to last link to tell
 			 * whether it's allocated object or not.
 			 */
-			link->next = -1 << OBJ_TAG_BITS;
+			link->next = -1UL << OBJ_TAG_BITS;
 		}
 		kunmap_atomic(vaddr);
 		page = next_page;