befs: fix sparse warning in linuxvfs.c

Use link as the variable name to avoid shadowing the arg.

fs/befs/linuxvfs.c:492:8: warning: symbol 'p' shadows an earlier one
fs/befs/linuxvfs.c:488:77: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: "Sergey S. Kostyliov" <rathamahata@php4.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>