[uaccess] Remove redundant user_to_virt()

The user_to_virt() function is now a straightforward wrapper around
addition, with the addend almost invariably being zero.

Remove this redundant wrapper.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/interface/linux/linux_smbios.c

@@ -59,7 +59,7 @@ static int linux_find_smbios ( struct smbios *smbios ) {
 		       smbios_entry_filename, strerror ( rc ) );
 		goto err_entry;
 	}
-	data = user_to_virt ( entry, 0 );
+	data = entry;
 	smbios3_entry = data;
 	smbios_entry = data;
 	if ( ( len >= ( ( int ) sizeof ( *smbios3_entry ) ) ) &&