FS-Cache: Remove unneeded null checks

fscache_write_op() makes unnecessary checks of the page variable to see if it
is NULL.  It can't be NULL at those points as the kernel would already have
crashed a little higher up where we examined page->index.

Furthermore, unless radix_tree_gang_lookup_tag() can return 1 but no page, a
NULL pointer crash should not be encountered there as we can only get there if
r_t_g_l_t() returned 1.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fscache/page.c

@@ -710,30 +710,26 @@ static void fscache_write_op(struct fscache_operation *_op)
 		goto superseded;
 	}
 
-	if (page) {
-		radix_tree_tag_set(&cookie->stores, page->index,
-				   FSCACHE_COOKIE_STORING_TAG);
-		radix_tree_tag_clear(&cookie->stores, page->index,
-				     FSCACHE_COOKIE_PENDING_TAG);
-	}
+	radix_tree_tag_set(&cookie->stores, page->index,
+			   FSCACHE_COOKIE_STORING_TAG);
+	radix_tree_tag_clear(&cookie->stores, page->index,
+			     FSCACHE_COOKIE_PENDING_TAG);
 
 	spin_unlock(&cookie->stores_lock);
 	spin_unlock(&object->lock);
 
-	if (page) {
-		fscache_set_op_state(&op->op, "Store");
-		fscache_stat(&fscache_n_store_pages);
-		fscache_stat(&fscache_n_cop_write_page);
-		ret = object->cache->ops->write_page(op, page);
-		fscache_stat_d(&fscache_n_cop_write_page);
-		fscache_set_op_state(&op->op, "EndWrite");
-		fscache_end_page_write(object, page);
-		if (ret < 0) {
-			fscache_set_op_state(&op->op, "Abort");
-			fscache_abort_object(object);
-		} else {
-			fscache_enqueue_operation(&op->op);
-		}
+	fscache_set_op_state(&op->op, "Store");
+	fscache_stat(&fscache_n_store_pages);
+	fscache_stat(&fscache_n_cop_write_page);
+	ret = object->cache->ops->write_page(op, page);
+	fscache_stat_d(&fscache_n_cop_write_page);
+	fscache_set_op_state(&op->op, "EndWrite");
+	fscache_end_page_write(object, page);
+	if (ret < 0) {
+		fscache_set_op_state(&op->op, "Abort");
+		fscache_abort_object(object);
+	} else {
+		fscache_enqueue_operation(&op->op);
 	}
 
 	_leave("");