Grow_continue_command: ensure 'content' is properly initialised.

Grow_continue_command: ensure 'content' is properly initialised.

Grow_continue_command() call verify_reshape_position(), which assumes
that info->sys_name is initialised.
'info' in verify_reshape_position() is 'content' in Grow_continue_command().

In the st->ss->external != 0 branch of that function, sysfs_init() is called
to initialize content->sys_name.
In the st->ss->external == 0 branch, ->sys_name is not initialized so
verify_reshape_position() will not do the right thing.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>