Removes f_rng parameter from mbedtls_rsa_pkcs1_verify

Commit removes f_rng parameter from
mbedtls_rsa_pkcs1_verify as a prerequisite
to removing the mode parameter. f_rng no
longer has relevance in this function if
mode is removed.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 9f4c187..fbcfdb1 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -90,7 +90,7 @@
     if( sig_len < rsa_len )
         return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
 
-    if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL, NULL,
+    if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL,
                                   MBEDTLS_RSA_PUBLIC, md_alg,
                                   (unsigned int) hash_len, hash, sig ) ) != 0 )
         return( ret );