net: ipc_router: Reorganize reader work item

Each error handling scenario in the reader work item has redundant code.
Reorganize the error handling to redunce redundancy.

Change-Id: I9e0f34502589e1c5473fa883ab985fa42c82b241
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>