Documentation/driver-api: dmaengine/provider: drop doubled word

Drop the doubled word "has".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Link: https://lore.kernel.org/r/20200704034502.17199-2-rdunlap@infradead.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/driver-api/dmaengine/provider.rst

@@ -507,7 +507,7 @@ dma_cookie_t
 DMA_CTRL_ACK
 
 - If clear, the descriptor cannot be reused by provider until the
-  client acknowledges receipt, i.e. has has a chance to establish any
+  client acknowledges receipt, i.e. has a chance to establish any
   dependency chains
 
 - This can be acked by invoking async_tx_ack()