libFLAC/bitwriter.c: Fix undefined behaviour

src/libFLAC/bitwriter.c

@@ -184,7 +184,7 @@ void FLAC__bitwriter_dump(const FLAC__BitWriter *bw, FILE *out)
 		for(i = 0; i < bw->words; i++) {
 			fprintf(out, "%08X: ", i);
 			for(j = 0; j < FLAC__BITS_PER_WORD; j++)
-				fprintf(out, "%01u", bw->buffer[i] & (1 << (FLAC__BITS_PER_WORD-j-1)) ? 1:0);
+				fprintf(out, "%01u", bw->buffer[i] & (1u << (FLAC__BITS_PER_WORD-j-1)) ? 1:0);
 			fprintf(out, "\n");
 		}
 		if(bw->bits > 0) {