isdn: use constants instead of magicnumbers

This patch changes instances of magic numbers like 4 and 8 to equivalent
constants.

The Coccinelle semantic patch used for making the change is as follows:

// <smpl>
@r@
type T;
T E;
identifier fld;
identifier c;
@@

E->fld & c

@s@
constant C;
identifier r.c;
@@

#define c C

@@
r.T E;
identifier r.fld;
identifier r.c;
constant s.C;
@@

 E->fld &
- C
+ c
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/i4l/isdn_net.c

@@ -2918,8 +2918,8 @@ isdn_net_getcfg(isdn_net_ioctl_cfg *cfg)
 			cfg->callback = 2;
 		cfg->cbhup = (lp->flags & ISDN_NET_CBHUP) ? 1 : 0;
 		cfg->dialmode = lp->flags & ISDN_NET_DIALMODE_MASK;
-		cfg->chargehup = (lp->hupflags & 4) ? 1 : 0;
-		cfg->ihup = (lp->hupflags & 8) ? 1 : 0;
+		cfg->chargehup = (lp->hupflags & ISDN_CHARGEHUP) ? 1 : 0;
+		cfg->ihup = (lp->hupflags & ISDN_INHUP) ? 1 : 0;
 		cfg->cbdelay = lp->cbdelay;
 		cfg->dialmax = lp->dialmax;
 		cfg->triggercps = lp->triggercps;