Get rid of spurious check in ffs_truncate for i_size == length

which fails to set the modification time on the file. The same
check a few lines later takes the correct action.

Submitted by:	Ian Dowse <iedowse@maths.tcd.ie>

sys/ufs/ffs/ffs_inode.c

@@ -151,8 +151,6 @@ ffs_truncate(vp, length, flags, cred, p)
 	off_t osize;
 
 	oip = VTOI(ovp);
-	if (oip->i_size == length)
-		return (0);
 	fs = oip->i_fs;
 	if (length < 0)
 		return (EINVAL);