staging: hv: remove ASSERT()s and return -EINVAL in RingBuffer.c

return -EINVAL instead of calling ASSERT() for these conditionals.
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>

drivers/staging/hv/RingBuffer.c

@@ -490,7 +490,8 @@ int RingBufferRead(RING_BUFFER_INFO *InRingInfo, void *Buffer,
 	u64 prevIndices = 0;
 	unsigned long flags;
 
-	ASSERT(BufferLen > 0);
+	if (BufferLen <= 0)
+		return -EINVAL;
 
 	spin_lock_irqsave(&InRingInfo->ring_lock, flags);