[PATCH] fix sparse warnings from {asm,net}/checksum.h

Rename the variable "sum" in the __range_ok macros to avoid name collisions
causing lots of "symbol shadows an earlier one" warnings by sparse.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Andi Kleen <ak@suse.de>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Acked-by: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>