Staging: hv: move ASSERT(scmnd) to a more useful location

There's not much point to make sure scmnd is not NULL after an assert
that would dereference scmnd.  The ASSERT()'s should be removed, but
until they are at least they at least can be in the right order.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>