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

Replace cmxchg by cmpxchg.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Roman Kisel <vdso@mailbox.org>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Author: JuliaLawall

drivers/hv/hyperv_vmbus.h

@@ -375,7 +375,7 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 		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