linuxthreads: fix compile error for non-MMU

Otherwise you get following linking error, because
of missing functions in libc.a:
undefined reference to `__libc_enable_asynccancel'

Fix by Thorsten Glaser while hacking session.

libpthread/linuxthreads/Makefile.in

@@ -65,7 +65,7 @@ CFLAGS-OMIT-libc_pthread_init.c := $(CFLAGS-dir_linuxthreads)
 libpthread_libc_CSRC := \
 	forward.c libc-cancellation.c libc_pthread_init.c # alloca_cutoff.c
 libpthread_libc_OBJ  := $(patsubst %.c, $(libpthread_OUT)/%.o,$(libpthread_libc_CSRC))
-libc-static-y += $(libpthread_OUT)/libc_pthread_init.o
+libc-static-y += $(libpthread_OUT)/libc_pthread_init.o $(libpthread_OUT)/libc-cancellation.o
 libc-shared-y += $(libpthread_libc_OBJ:.o=.oS)
 
 libpthread-static-y += $(patsubst %,$(libpthread_OUT)/%.o,$(libpthread_static_SRC))