staging: lustre: remove invariant in cl_io_read_ahead()

This invariant can fail as ci_type is somtimes CIS_INIT.

According to Jinshan Xiong, or of the most recent significant
change to this code, "We should get rid of it."

So do that.

Fixes: 1e1db2a9 ("staging: lustre: clio: Revise read ahead implementation")
Cc: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/obdclass/cl_io.c

@@ -599,7 +599,6 @@ int cl_io_read_ahead(const struct lu_env *env, struct cl_io *io,
 	int		       result = 0;
 
 	LINVRNT(io->ci_type == CIT_READ || io->ci_type == CIT_FAULT);
-	LINVRNT(io->ci_state == CIS_IO_GOING || io->ci_state == CIS_LOCKED);
 	LINVRNT(cl_io_invariant(io));
 
 	cl_io_for_each(scan, io) {