[PATCH] drivers/isdn: Handcrafted MIN/MAX Macro removal

Cleanups done to use min/max macros from kernel.h.  Handcrafted MIN/MAX
macros are changed to use macros in kernel.h

[akpm@osdl.org: warning fix]
Signed-off-by: Amol Lad <amol@verismonetworks.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>