vfs: introduce adjustable ISO9660 buffer length for file reading

src/fs/vfs.c

@@ -71,9 +71,9 @@ size_t vfs_read_file(l9660_file *file, uint8_t* buffer)
     l9660_status status;
 
     for(;;) {
-        char buf[128];
+        char buf[ISO_9660_BUFFER_LENGTH];
         size_t read;
-        status = l9660_read(file, buf, 128, &read);
+        status = l9660_read(file, buf, ISO_9660_BUFFER_LENGTH, &read);
 
         if (status != L9660_OK) {
             printf("An error occurred during file read!\n");
@@ -97,8 +97,8 @@ size_t vfs_read_file_length(l9660_file *file, uint8_t* buffer, size_t length)
     l9660_status status;
 
     while(total_read < length) {
-        char buf[128];
-        size_t to_read = (length - total_read) < 128 ? (length - total_read) : 128;
+        char buf[ISO_9660_BUFFER_LENGTH];
+        size_t to_read = (length - total_read) < ISO_9660_BUFFER_LENGTH ? (length - total_read) : ISO_9660_BUFFER_LENGTH;
         size_t read = 0;
 
         status = l9660_read(file, buf, to_read, &read);