archive/iso9660: simplify _read()

src/archive/Iso9660ArchivePlugin.cxx

@@ -201,7 +201,9 @@ iso9660_input_read(InputStream *is, void *ptr, size_t size,
 	} else {
 		no_blocks = size / ISO_BLOCKSIZE;
 	}
-	if (no_blocks > 0) {
+
+	if (no_blocks == 0)
+		return 0;
 
 	cur_block = is->offset / ISO_BLOCKSIZE;
 
@@ -219,7 +221,6 @@ iso9660_input_read(InputStream *is, void *ptr, size_t size,
 	}
 
 	is->offset += readed;
-	}
 	return readed;
 }