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 <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-npcm-fiu.c

···
 #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>
 
···
 
 	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,