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 <rdunlap@infradead.org>
Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: James Morris <james.l.morris@oracle.com>
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index b27535a..399433a 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -176,7 +176,7 @@
 	    && 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;
@@ -530,14 +530,15 @@
 			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);