Use a proper type for the variable holding the summary size of the inode

data. Otherwise, on 32bit systems, unlinked inode which size is the
multiple of 4GB was not truncated, causing corruption.

Reported by:	brucec
Reviewed by:	mckusick
Tested by:	pho

sys/ufs/ufs/ufs_inode.c

@@ -76,7 +76,7 @@ ufs_inactive(ap)
 	struct thread *td = ap->a_td;
 	mode_t mode;
 	int error = 0;
-	int isize;
+	off_t isize;
 	struct mount *mp;
 
 	mp = NULL;