mm: frontswap: make all branches of if statement in put page consistent

Currently it has a complex structure where different things are compared
at each branch. Simplify that and make both branches look similar.
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

mm/frontswap.c

@@ -140,16 +140,16 @@ int __frontswap_store(struct page *page)
 		inc_frontswap_succ_stores();
 		if (!dup)
 			atomic_inc(&sis->frontswap_pages);
-	} else if (dup) {
+	} else {
 		/*
 		  failed dup always results in automatic invalidate of
 		  the (older) page from frontswap
 		 */
-		frontswap_clear(sis, offset);
-		atomic_dec(&sis->frontswap_pages);
-		inc_frontswap_failed_stores();
-	} else {
 		inc_frontswap_failed_stores();
+		if (dup) {
+			frontswap_clear(sis, offset);
+			atomic_dec(&sis->frontswap_pages);
+		}
 	}
 	if (frontswap_writethrough_enabled)
 		/* report failure so swap also writes to swap device */