Use mbedtls_xor in Camellia

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/camellia.c b/library/camellia.c
index 5dd6c56..6e781c7 100644
--- a/library/camellia.c
+++ b/library/camellia.c
@@ -526,7 +526,6 @@
                                 const unsigned char *input,
                                 unsigned char *output )
 {
-    int i;
     unsigned char temp[16];
     if( mode != MBEDTLS_CAMELLIA_ENCRYPT && mode != MBEDTLS_CAMELLIA_DECRYPT )
         return MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA;
@@ -541,8 +540,7 @@
             memcpy( temp, input, 16 );
             mbedtls_camellia_crypt_ecb( ctx, mode, input, output );
 
-            for( i = 0; i < 16; i++ )
-                output[i] = (unsigned char)( output[i] ^ iv[i] );
+            mbedtls_xor( output, output, iv, 16 );
 
             memcpy( iv, temp, 16 );
 
@@ -555,8 +553,7 @@
     {
         while( length > 0 )
         {
-            for( i = 0; i < 16; i++ )
-                output[i] = (unsigned char)( input[i] ^ iv[i] );
+            mbedtls_xor( output, input, iv, 16 );
 
             mbedtls_camellia_crypt_ecb( ctx, mode, output, output );
             memcpy( iv, output, 16 );