Fix warnings and errors reported by gcc

src/argparse.c

@@ -7,10 +7,9 @@ argparser_t parse_args(i32 argc, char *argv[]) {
     return (argparser_t){0};
   }
 
-  argparser_t output = {
-      .succeeded = true,
-      .args = (pckr_args_t){0},
-  };
+  argparser_t output = {0};
+  output.succeeded = true;
+  output.args = (pckr_args_t){0};
 
   realpath(argv[1], output.args.dir);
   realpath(argv[2], output.args.output);