mtd: afs: break out v1 footer magic to a define

Break out the magic number to a #defined constant.

Cc: Ryan Harkin <[e-mail]>
Cc: Liviu Dudau <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>
Signed-off-by: Brian Norris <[e-mail]>

drivers/mtd/afs.c

···
 #include <linux/mtd/map.h>
 #include <linux/mtd/partitions.h>
 
+#define AFSV1_FOOTER_MAGIC 0xA0FFFF9F
+
 struct footer_v1 {
 	u32 image_info_base;	/* Address of first word of ImageFooter  */
 	u32 image_start;	/* Start of area reserved by this footer */
···
 	/*
 	 * Does it contain the magic number?
 	 */
-	if (fs.signature != 0xa0ffff9f)
+	if (fs.signature != AFSV1_FOOTER_MAGIC)
 		ret = 0;
 
 	/*