Drivers: hv: vmbus: Cleanup synic memory free path

Drivers: hv: vmbus: Cleanup synic memory free path

[ Upstream commit 572086325ce9a9e348b8748e830653f3959e88b6 ]

clk_evt memory is not being freed when the synic is shutdown
or when there is an allocation error.  Add the appropriate
kfree() call, along with a comment to clarify how the memory
gets freed after an allocation error.  Make the free path
consistent by removing checks for NULL since kfree() and
free_page() already do the check.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>