Fix sparc32 build error due to undefined bool type.

CC [M] fs/ocfs2/dlm/userdlm.o
In file included from include/asm/sigcontext.h:6,
from include/asm/signal.h:5,
from include/linux/signal.h:4,
from fs/ocfs2/dlm/userdlm.c:30:
include/asm/ptrace.h:42: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or 
‘__attribute__’ before ‘pt_regs_is_syscall’
include/asm/ptrace.h:47: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or 
‘__attribute__’ before ‘pt_regs_clear_syscall’
make[3]: *** [fs/ocfs2/dlm/userdlm.o] Error 1
make[2]: *** [fs/ocfs2/dlm] Error 2
make[1]: *** [fs/ocfs2] Error 2
make: *** [fs] Error 2
Signed-off-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>