Fix syntax error </ref>

bip-segwit-checksig.mediawiki

@@ -35,7 +35,7 @@ A new transaction digest algorithm is defined, but only applicable to sigops in
      9. nLocktime of the transaction
     10. sighash type of the signature
 
-The items 1, 4, 5, 7, 9, 10 have the same meaning as the original algorithm. <ref name=wiki>
+The items 1, 4, 5, 7, 9, 10 have the same meaning as the original algorithm. <ref name=wiki></ref>
 
 The item 6 is a 8-byte value of the amount of bitcoin spent in this input.
 
@@ -56,7 +56,7 @@ The hashPrevouts, hashSequence, and hashOutputs calculated in an earlier verific
 
 Refer to the reference implementation, reproduced below, for the precise algorithm:
 
-  
+<source lang="cpp">
   uint256 hashPrevouts;
   uint256 hashSequence;
   uint256 hashOutputs;
@@ -110,6 +110,7 @@ Refer to the reference implementation, reproduced below, for the precise algorit
   ss << nHashType;
 
   return ss.GetHash();
+</source>
 
 == Deployment ==