fixing qoi_decode() declaration

encoder/3rdparty/qoi.h

diff --git a/encoder/3rdparty/qoi.h b/encoder/3rdparty/qoi.h
index f9236fa..5f55079 100644
--- a/encoder/3rdparty/qoi.h
+++ b/encoder/3rdparty/qoi.h
@@ -286,7 +286,7 @@
 
 The returned pixel data should be free()d after use. */
 
-void *qoi_decode(const void *data, int size, qoi_desc *desc, int channels);
+void *qoi_decode(const void *data, size_t size, qoi_desc *desc, int channels);
 
 
 #ifdef __cplusplus