sgi-gru: call fs_initcall() if statically linked

If xpc.ko and gru.ko are both statically linked into the kernel, then
xpc_init() can get called before gru_init() and make a call to one of the
gru's exported functions before the gru has initialized itself. The end
result is a NULL dereference.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>