asn1c code for windows platform fixed, thanks to rmeub@users.sourceforge.net

diff --git a/libasn1compiler/asn1c_save.c b/libasn1compiler/asn1c_save.c
index 0eb70c9..e0a2f67 100644
--- a/libasn1compiler/asn1c_save.c
+++ b/libasn1compiler/asn1c_save.c
@@ -353,7 +353,7 @@
 
 	while(!feof(fpsrc)) {
 		len = fread(buf, 1, sizeof(buf), fpsrc);
-		if(fwrite(buf, 1, len, fpsrc) != len) {
+		if(fwrite(buf, 1, len, fpdst) != len) {
 			errno = EIO;
 			retval = -1;
 			break;