cnss2: Set RDDM done only when dump is collected

This can help retry dump collection in kernel panic handler if
something goes wrong in normal path. Also return proper value
for cnss_force_collect_rddm() when RDDM is done successfully.

Change-Id: Icf1dabb0313162c459839c52119420f65f73d5c1
Signed-off-by: Yue Ma <yuem@codeaurora.org>