msm: ipa3: Fix xDCI channel emptiness check

Current implementation to check the emptiness in a loop
was to query the indicators from the H/W once, and then loop
on them to check emptiness. This was fixed by reading the
indicators on each loop as should be.

Change-Id: If2b944376db5f029603d7f6181c805b13440c61d
Signed-off-by: Ghanim Fodi <gfodi@codeaurora.org>