fix doxygen

Author: Remi Delmas

src/goto-instrument/contracts/doc/developer/contracts-dev-arch.md

@@ -29,7 +29,7 @@ Each of these translation passes is implemented in a specific class:
  @ref dfcc_instrumentt           | Implements @ref contracts-dev-spec-dfcc for @ref goto_functiont, @ref goto_programt, or subsequences of instructions of @ref goto_programt
  @ref dfcc_is_fresht             | Implements @ref contracts-dev-spec-is-fresh
  @ref dfcc_pointer_in_ranget     | Implements @ref contracts-dev-spec-pointer-in-range
- @ref dfcc_pointer_euqalst       | Implements @ref contracts-dev-spec-pointer-equals
+ @ref dfcc_pointer_equalst       | Implements @ref contracts-dev-spec-pointer-equals
  @ref dfcc_lift_memory_predicatest | Implements @ref contracts-dev-spec-memory-predicates-rewriting
  @ref dfcc_is_freeablet          | Implements @ref contracts-dev-spec-is-freeable
  @ref dfcc_obeys_contractt       | Implements @ref contracts-dev-spec-obeys-contract