dmaengine: ste_dma40: remove redundant irqsave and irqrestore in hardIRQ

Running in hardIRQ, disabling IRQ is redundant since hardIRQ has disabled
IRQ. This patch removes the irqsave and irqstore to save some instruction
cycles.
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201027215252.25820-10-song.bao.hua@hisilicon.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/ste_dma40.c

@@ -1643,13 +1643,12 @@ static irqreturn_t d40_handle_interrupt(int irq, void *data)
 	u32 row;
 	long chan = -1;
 	struct d40_chan *d40c;
-	unsigned long flags;
 	struct d40_base *base = data;
 	u32 *regs = base->regs_interrupt;
 	struct d40_interrupt_lookup *il = base->gen_dmac.il;
 	u32 il_size = base->gen_dmac.il_size;
 
-	spin_lock_irqsave(&base->interrupt_lock, flags);
+	spin_lock(&base->interrupt_lock);
 
 	/* Read interrupt status of both logical and physical channels */
 	for (i = 0; i < il_size; i++)
@@ -1694,7 +1693,7 @@ static irqreturn_t d40_handle_interrupt(int irq, void *data)
 		spin_unlock(&d40c->lock);
 	}
 
-	spin_unlock_irqrestore(&base->interrupt_lock, flags);
+	spin_unlock(&base->interrupt_lock);
 
 	return IRQ_HANDLED;
 }