selftest supports cmac if only MBEDTLS_DES_C is defined
Other minor typo fixes
diff --git a/library/error.c b/library/error.c
index 8c38cf2..7ec8420 100644
--- a/library/error.c
+++ b/library/error.c
@@ -587,6 +587,8 @@
         mbedtls_snprintf( buf, buflen, "CMAC - Bad input parameters to function" );
     if( use_ret == -(MBEDTLS_ERR_CMAC_VERIFY_FAILED) )
         mbedtls_snprintf( buf, buflen, "CMAC - Verification failed" );
+    if( use_ret == -(MBEDTLS_ERR_CMAC_ALLOC_FAILED) )
+        mbedtls_snprintf( buf, buflen, "CMAC - Failed to allocate memory" );
 #endif /* MBEDTLS_CMAC_C */
 
 #if defined(MBEDTLS_CTR_DRBG_C)