Allow space(s) between "__attribute__" and "((blah))" so that
kernel-doc does not complain like:

Warning(/tester/linsrc/linux-2.6.20-git15//kernel/timer.c:939): No description found for parameter 'read_persistent_clock(void'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>