net: qualcomm: rmnet: Remove the rmnet_map_results enum

Only the success and consumed entries were actually in use.
Use standard error codes instead.

CRs-Fixed: 2156182
Change-Id: Iae0aba041f7e47c5afa3e517a6cc1563da374d7d
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>