spi: spi-xilinx: cleanup a check in xilinx_spi_txrx_bufs()

'!' has higher precedence than comparisons so the original condition is equivalent to "if (xspi->remaining_bytes = 0)". This makes the static checkers complain.

xspi->remaining_bytes is signed and from looking at the code briefly, I think it might be able to go negative. I suspect that going negative may cause a bug, but I don't have the hardware and can't test.

index 0b8398c..fb56fcf 100644
@@ -301,7 +301,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 		}
 
 		/* See if there is more data to send */
-		if (!xspi->remaining_bytes > 0)
+		if (xspi->remaining_bytes <= 0)
 			break;
 	}
 

Applied, thanks.