Some fixes for building

Author: vcsjones

snippets/cpp/VS_Snippets_CLR/HMACRIPEMD160/CPP/makefile

@@ -0,0 +1,2 @@
+System.Security.Cryptography.HMACRIPEMD160.exe: hmacripemd160.cpp
+    cl /FeSystem.Security.Cryptography.HMACRIPEMD160.exe /clr:pure hmacripemd160.cpp

snippets/cpp/VS_Snippets_CLR/HMACSHA256/CPP/makefile

@@ -0,0 +1,2 @@
+System.Security.Cryptography.HMACSHA256.exe: hmacsha256.cpp 
+    cl /FeSystem.Security.Cryptography.HMACSHA256.exe /clr:pure hmacsha256.cpp

snippets/cpp/VS_Snippets_CLR/HMACSHA384/CPP/makefile

@@ -0,0 +1,2 @@
+System.Security.Cryptography.HMACSHA384.exe: hmacsha384.cpp 
+    cl /FeSystem.Security.Cryptography.HMACSHA384.exe /clr:pure hmacsha384.cpp

snippets/cpp/VS_Snippets_CLR/HMACSHA512/CPP/makefile

@@ -0,0 +1,2 @@
+System.Security.Cryptography.HMACSHA512.exe: hmacsha512.cpp 
+    cl /FeSystem.Security.Cryptography.HMACSHA512.exe /clr:pure hmacsha512.cpp

snippets/csharp/System.Security.Cryptography/PasswordDeriveBytes/Overview/sample.cs

@@ -82,7 +82,7 @@ public static byte[] CreateRandomSalt(int length)
         using (RandomNumberGenerator rng = RandomNumberGenerator.Create())
         {
             // Fill the buffer with random bytes.
-            rand.GetBytes(randBytes);
+            rng.GetBytes(randBytes);
         }
 
         // return the bytes.