sha256: cast shift to uint64_t

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/crc/sha256.c b/crc/sha256.c
index ae9ff4d..2fd17a3 100644
--- a/crc/sha256.c
+++ b/crc/sha256.c
@@ -277,7 +277,7 @@
 	static const uint8_t padding[64] = { 0x80, };
 
 	/* Save number of bits */
-	bits = sctx->count << 3;
+	bits = (uint64_t) sctx->count << 3;
 
 	/* Pad out to 56 mod 64. */
 	index = sctx->count & 0x3f;