msm: camera: lrme: Change list iterator api during requests deletion

list_for_each_entry will break if we delete something while iterating
the list. it may result in an infinite loop and make CPU busy for
a longer time.

This change prevents to enter such condition.

Change-Id: I9d9ebdd9b2e00832e3493d73de4ba2ea3745a630
Signed-off-by: Chandan Kumar Jha <cjha@codeaurora.org>