Staging: hv: fix up printk warnings

After LogMsg was converted to printk, lots of build warnings showed up
as no one was checking the arguments to LogMsg.  This patch fixes them
all.

Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>