Use UINT64_C instead of unsigned long long integer constant.

Change-Id: Id181957956ccaacc6c29b641a1f1144886d442c0
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
Reviewed-on: https://boringssl-review.googlesource.com/7630
Reviewed-by: David Benjamin <davidben@google.com>

crypto/poly1305/poly1305_vec.c

diff --git a/crypto/poly1305/poly1305_vec.c b/crypto/poly1305/poly1305_vec.c
index 59aab19..3045a2f 100644
--- a/crypto/poly1305/poly1305_vec.c
+++ b/crypto/poly1305/poly1305_vec.c
@@ -701,9 +701,9 @@
   t0 &= 0x3ffffff;
   t1 = t1 + c;
 
-  st->HH[0] = ((t0) | (t1 << 26)) & 0xfffffffffffull;
-  st->HH[1] = ((t1 >> 18) | (t2 << 8) | (t3 << 34)) & 0xfffffffffffull;
-  st->HH[2] = ((t3 >> 10) | (t4 << 16)) & 0x3ffffffffffull;
+  st->HH[0] = ((t0) | (t1 << 26)) & UINT64_C(0xfffffffffff);
+  st->HH[1] = ((t1 >> 18) | (t2 << 8) | (t3 << 34)) & UINT64_C(0xfffffffffff);
+  st->HH[2] = ((t3 >> 10) | (t4 << 16)) & UINT64_C(0x3ffffffffff);
 
   return consumed;
 }