Fix a couple of harmless clang3.2 warnings

changes/clang_enum_warnings

@@ -0,0 +1,3 @@
+  o Code simplifications and refactoring:
+    - Get rid of a couple of harmless clang warnings, where we compared
+      enums to ints. These warnings are newly introduced in clang 3.2.

src/common/crypto.c

@@ -1458,7 +1458,7 @@ crypto_digest256(char *digest, const char *m, size_t len,
 int
 crypto_digest_all(digests_t *ds_out, const char *m, size_t len)
 {
-  digest_algorithm_t i;
+  int i;
   tor_assert(ds_out);
   memset(ds_out, 0, sizeof(*ds_out));
   if (crypto_digest(ds_out->d[DIGEST_SHA1], m, len) < 0)

src/or/dirvote.c

@@ -2223,7 +2223,7 @@ networkstatus_add_detached_signatures(networkstatus_t *target,
   {
     digests_t *digests = strmap_get(sigs->digests, flavor);
     int n_matches = 0;
-    digest_algorithm_t alg;
+    int alg;
     if (!digests) {
       *msg_out = "No digests for given consensus flavor";
       return -1;
@@ -3471,7 +3471,7 @@ dirvote_free_all(void)
 const char *
 dirvote_get_pending_consensus(consensus_flavor_t flav)
 {
-  tor_assert(((int)flav) >= 0 && flav < N_CONSENSUS_FLAVORS);
+  tor_assert(((int)flav) >= 0 && (int)flav < N_CONSENSUS_FLAVORS);
   return pending_consensuses[flav].body;
 }