IMA: only allocate iint when needed

IMA always allocates an integrity structure to hold information about
every inode, but only needed this structure to track the number of
readers and writers currently accessing a given inode.  Since that
information was moved into struct inode instead of the integrity struct
this patch stops allocating the integrity stucture until it is needed.
Thus greatly reducing memory usage.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/security/security.c b/security/security.c
index c53949f..a3b47fe 100644
--- a/security/security.c
+++ b/security/security.c
@@ -333,16 +333,8 @@
 
 int security_inode_alloc(struct inode *inode)
 {
-	int ret;
-
 	inode->i_security = NULL;
-	ret =  security_ops->inode_alloc_security(inode);
-	if (ret)
-		return ret;
-	ret = ima_inode_alloc(inode);
-	if (ret)
-		security_inode_free(inode);
-	return ret;
+	return security_ops->inode_alloc_security(inode);
 }
 
 void security_inode_free(struct inode *inode)