Readability improvements

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/psa_crypto_rsa.c b/library/psa_crypto_rsa.c
index de17e5d..3b71913 100644
--- a/library/psa_crypto_rsa.c
+++ b/library/psa_crypto_rsa.c
@@ -456,7 +456,7 @@
         return( MBEDTLS_RSA_SALT_LEN_ANY );
     /* Otherwise: standard salt length, i.e. largest possible salt length
      * up to the hash length. */
-    int klen = (int) (int) mbedtls_rsa_get_len( rsa ); // known to fit
+    int klen = (int) mbedtls_rsa_get_len( rsa ); // known to fit
     int hlen = (int) hash_length; // known to fit
     int room = klen - 2 - hlen;
     if( room < 0 )