spi: npcm-fiu: use min_t() to improve code

Use min_t() to reduce the code in npcm_fiu_read() and improve its
readability.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Link: https://patch.msgid.link/20250815082118.586422-3-rongqianfeng@vivo.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: qianfengrong

drivers/spi/spi-npcm-fiu.c

@@ -13,6 +13,7 @@
 #include <linux/vmalloc.h>
 #include <linux/regmap.h>
 #include <linux/of.h>
+#include <linux/minmax.h>
 #include <linux/spi/spi-mem.h>
 #include <linux/mfd/syscon.h>
 
@@ -498,10 +499,7 @@ static int npcm_fiu_read(struct spi_mem *mem, const struct spi_mem_op *op)
 
 	do {
 		addr = ((u32)op->addr.val + i);
-		if (currlen < 16)
-			readlen = currlen;
-		else
-			readlen = 16;
+		readlen = min_t(int, currlen, 16);
 
 		buf_ptr = data + i;
 		ret = npcm_fiu_uma_read(mem, op, addr, true, buf_ptr,