staging: vt6655: s_vGenerateTxParameter removed nested pvRrvTime NULL check

Just do single NULL check on pvRrvTime and return.

If pvRrvTime is NULL none of the if statements are valid.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>