ftl: simplify calculations in ftl_read()/ftl_write() and remove an out-dated check

source/ftl/ftl.c

@@ -28,8 +28,7 @@ size_t ftl_read(struct ftl_map *map, void *data, size_t len, uint32_t va)
 	if (!data)
 		return 0;
 
-	mask = ((1 << map->log2_page_size) - 1);
-	offset = va & mask;
+	offset = va & ((1 << map->log2_page_size) - 1);
 	va >>= map->log2_page_size;
 	len = min(len, (1 << map->log2_page_size) - offset);
 
@@ -48,14 +47,12 @@ size_t ftl_write(struct ftl_map *map, uint32_t va, const void *udata,
 	char data[1 << map->log2_page_size];
 	struct ftl_page_desc page_desc;
 	int ret;
-	uint32_t mask, offset, page;
+	uint32_t offset, page;
 
-	if (va >= ftl_get_capacity(map) &&
-	    !is_aligned(va, 1 << map->log2_page_size))
+	if (va >= ftl_get_capacity(map))
 		return 0;
 
-	mask = ((1 << map->log2_page_size) - 1);
-	offset = va & mask;
+	offset = va & ((1 << map->log2_page_size) - 1);
 	va >>= map->log2_page_size;
 
 	if ((ret = trace_path(map, &page_desc, &page, va)) < 0 &&