Drivers: hv: vmbus: fix typo in function name reference

Replace cmxchg by cmpxchg.

Signed-off-by: Julia Lawall <[e-mail]>
Reviewed-by: Roman Kisel <[e-mail]>
Signed-off-by: Wei Liu <[e-mail]>

drivers/hv/hyperv_vmbus.h

···
 		return;
 
 	/*
-	 * The cmxchg() above does an implicit memory barrier to
+	 * The cmpxchg() above does an implicit memory barrier to
 	 * ensure the write to MessageType (ie set to
 	 * HVMSG_NONE) happens before we read the
 	 * MessagePending and EOMing. Otherwise, the EOMing