spi: wpcm-fiu: Fix potential NULL pointer dereference in wpcm_fiu_probe()

platform_get_resource_byname() can return NULL, which would cause a crash
when passed the pointer to resource_size().

Move the fiu->memory_size assignment after the error check for
devm_ioremap_resource() to prevent the potential NULL pointer dereference.

Fixes: 9838c18 ("spi: wpcm-fiu: Add direct map support")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: J. Neuschäfer <j.ne@posteo.net>
Link: https://patch.msgid.link/20260212-wpcm-v1-1-5b7c4f526aac@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: outman119

drivers/spi/spi-wpcm-fiu.c

@@ -459,11 +459,11 @@ static int wpcm_fiu_probe(struct platform_device *pdev)
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "memory");
 	fiu->memory = devm_ioremap_resource(dev, res);
-	fiu->memory_size = min_t(size_t, resource_size(res), MAX_MEMORY_SIZE_TOTAL);
 	if (IS_ERR(fiu->memory))
 		return dev_err_probe(dev, PTR_ERR(fiu->memory),
 			       "Failed to map flash memory window\n");
 
+	fiu->memory_size = min_t(size_t, resource_size(res), MAX_MEMORY_SIZE_TOTAL);
 	fiu->shm_regmap = syscon_regmap_lookup_by_phandle_optional(dev->of_node, "nuvoton,shm");
 
 	wpcm_fiu_hw_init(fiu);