Add some error handling to oxfstool format and fix a couple of memory leaks

src/ox/fs/oxfstool.cpp

@@ -79,6 +79,11 @@ int format(int argc, char **args) {
 		printf("Size: %llu bytes\n", size);
 		printf("Type: %d\n", type);
 
+		if (size < sizeof(FileStore64)) {
+			err = 1;
+		}
+
+		if (err) {
 			// format
 			switch (type) {
 				case 16:
@@ -90,19 +95,25 @@ int format(int argc, char **args) {
 				case 64:
 					FileStore64::format(buff, size, ox::fs::OxFS_64);
 					break;
+				default:
+					err = 1;
 			}
-		createFileSystem(buff);
 
+			if (err) {
 				auto file = fopen(path, "wb");
 				if (file) {
-			fwrite(buff, size, 1, file);
+					err = fwrite(buff, size, 1, file);
-			err = fclose(file);
+					err |= fclose(file);
 					if (err) {
 						printf("Could not write to file: %s.\n", path);
 					}
 				} else {
 					printf("Could not open file: %s.\n", path);
 				}
+			}
+		}
+
+		free(buff);
 
 		if (err == 0) {
 			printf("Created file system %s\n", path);