Fix hash in haddock of ghc-prim.

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14653

Differential Revision: https://phabricator.haskell.org/D4305

(cherry picked from commit 2feed118)

compiler/prelude/primops.txt.pp

@@ -2621,7 +2621,7 @@ section "Unsafe pointer equality"
 
 primop  ReallyUnsafePtrEqualityOp "reallyUnsafePtrEquality#" GenPrimOp
    a -> a -> Int#
-   { Returns 1# if the given pointers are equal and 0# otherwise. }
+   { Returns {\texttt 1\#} if the given pointers are equal and {\texttt 0\#} otherwise. }
    with
    can_fail   = True -- See Note [reallyUnsafePtrEquality#]