Removes p_rng param from mbedtls_rsa_pkcs1_verify

Commit removes p_rng from mbedtls_rsa_pkcs1_verify
since p_rng has no relevance following the removal
of f_rng from this function.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/programs/pkey/rsa_verify.c b/programs/pkey/rsa_verify.c
index 60e1377..8f207c7 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, MBEDTLS_RSA_PUBLIC,
+    if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, 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 );