p54: drop device reference count if fails to enable device

commit 8149069db81853570a665f5e5648c0e526dc0e43 upstream.

The function p54p_probe takes an extra reference count of the PCI
device. However, the extra reference count is not dropped when it fails
to enable the PCI device. This patch fixes the bug.

Cc: stable@vger.kernel.org
Signed-off-by: Pan Bian <bianpan2016@163.com>
Acked-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>