fix argument omission in ABI-compat weak_alias for fscanf

src/stdio/fscanf.c

@@ -12,4 +12,4 @@ int fscanf(FILE *restrict f, const char *restrict fmt, ...)
 	return ret;
 }
 
-weak_alias(__isoc99_fscanf);
+weak_alias(fscanf, __isoc99_fscanf);