dmaengine: imx-sdma: Fix error checking in sdma_event_remap

of_parse_phandle() returns NULL on errors, rather than error
pointers. Using NULL check on grp_np to fix this.

Fixes: d078cd1b ("dmaengine: imx-sdma: Add imx6sx platform support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220308064952.15743-1-linmq006@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/imx-sdma.c

@@ -1885,7 +1885,7 @@ static int sdma_event_remap(struct sdma_engine *sdma)
 	u32 reg, val, shift, num_map, i;
 	int ret = 0;
 
-	if (IS_ERR(np) || IS_ERR(gpr_np))
+	if (IS_ERR(np) || !gpr_np)
 		goto out;
 
 	event_remap = of_find_property(np, propname, NULL);
@@ -1933,7 +1933,7 @@ static int sdma_event_remap(struct sdma_engine *sdma)
 	}
 
 out:
-	if (!IS_ERR(gpr_np))
+	if (gpr_np)
 		of_node_put(gpr_np);
 
 	return ret;