Add a safe wrapper for write and fix some warnings

1. Add a function writeall and make swrite wrap that function. Use either writeall or swrite, depending on whether we want to exit on errors or not.
2. Fix warnings when compiling with a higher optimisation level.
(CFLAGS ?= -pipe -O3 -march=native -mtune=native -freorder-blocks-and-partition)

Signed-off-by: hwangcc <hwangcc@csie.nctu.edu.tw>

src/load_layout.c

@@ -105,7 +105,7 @@ static int json_end_map(void *ctx) {
             int cnt = 1;
             while (workspace != NULL) {
                 FREE(json_node->name);
-                asprintf(&(json_node->name), "%s_%d", base, cnt++);
+                sasprintf(&(json_node->name), "%s_%d", base, cnt++);
                 workspace = NULL;
                 TAILQ_FOREACH(output, &(croot->nodes_head), nodes)
                 GREP_FIRST(workspace, output_get_content(output), !strcasecmp(child->name, json_node->name));