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/programs/pkey/rsa_verify.c b/programs/pkey/rsa_verify.c
index fbc0779..60e1377 100644
--- a/programs/pkey/rsa_verify.c
+++ b/programs/pkey/rsa_verify.c
@@ -140,7 +140,7 @@
         goto exit;
     }
 
-    if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL, MBEDTLS_RSA_PUBLIC,
+    if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, NULL, MBEDTLS_RSA_PUBLIC,
                                   MBEDTLS_MD_SHA256, 20, hash, buf ) ) != 0 )
     {
         mbedtls_printf( " failed\n  ! mbedtls_rsa_pkcs1_verify returned -0x%0x\n\n", (unsigned int) -ret );