block: fix part_pack_uuid() build error

Commit "85865c1 ima: add policy support for file system uuid"
introduced a CONFIG_BLOCK dependency. This patch defines a
wrapper called blk_part_pack_uuid(), which returns -EINVAL,
when CONFIG_BLOCK is not defined.

security/integrity/ima/ima_policy.c:538:4: error: implicit declaration
of function 'part_pack_uuid' [-Werror=implicit-function-declaration]

Changelog v2:
- Reference commit number in patch description
Changelog v1:
- rename ima_part_pack_uuid() to blk_part_pack_uuid()
- resolve scripts/checkpatch.pl warnings
Changelog v0:
- fix UUID scripts/Lindent msgs

Reported-by: Randy Dunlap <[e-mail]>
Reported-by: David Rientjes <[e-mail]>
Signed-off-by: Mimi Zohar <[e-mail]>
Acked-by: David Rientjes <[e-mail]>
Acked-by: Randy Dunlap <[e-mail]>
Cc: Jens Axboe <[e-mail]>
Signed-off-by: James Morris <[e-mail]>

include/linux/genhd.h

···
 	}
 }
 
+static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
+{
+	part_pack_uuid(uuid_str, to);
+	return 0;
+}
+
 static inline int disk_max_parts(struct gendisk *disk)
 {
 	if (disk->flags & GENHD_FL_EXT_DEVT)
···
 	return devt;
 }
 
+static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
+{
+	return -EINVAL;
+}
 #endif /* CONFIG_BLOCK */
 
 #endif /* _LINUX_GENHD_H */

security/integrity/ima/ima_policy.c

···
 	    && rule->fsmagic != inode->i_sb->s_magic)
 		return false;
 	if ((rule->flags & IMA_FSUUID) &&
-		memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
+	    memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
 		return false;
 	if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid))
 		return false;
···
 			ima_log_string(ab, "fsuuid", args[0].from);
 
 			if (memchr_inv(entry->fsuuid, 0x00,
-			    sizeof(entry->fsuuid))) {
+				       sizeof(entry->fsuuid))) {
 				result = -EINVAL;
 				break;
 			}
 
-			part_pack_uuid(args[0].from, entry->fsuuid);
-			entry->flags |= IMA_FSUUID;
-			result = 0;
+			result = blk_part_pack_uuid(args[0].from,
+						    entry->fsuuid);
+			if (!result)
+				entry->flags |= IMA_FSUUID;
 			break;
 		case Opt_uid:
 			ima_log_string(ab, "uid", args[0].from);