Drivers: hv: vmbus: Fix a bug in hv_need_to_signal()
Drivers: hv: vmbus: Fix a bug in hv_need_to_signal()

As part of updating the vmbus protocol, the function hv_need_to_signal()
was introduced. This functions helps optimize signalling from guest to
host. The newly added memory barrier is needed to ensure that we correctly
decide when to signal the host.

Signed-off-by: K. Y. Srinivasan <bcbf172338421f26297a2592698edf8cc84ecbef@microsoft.com>
Reviewed-by: Haiyang Zhang <6c26c5044f1d67d9ed5db6596adb36d25510e216@microsoft.com>
Reported-by: Olaf Hering <9d781ea8292a2154c6ca4a89a79e3c0c69f1ae9f@suse.de>
Cc: Stable <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org>  (V3.8+)
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs