Camera2Session: Add return statements after reportError where needed.
Camera2Session: Add return statements after reportError where needed.

BUG=webrtc:7117

Review-Url: https://codereview.webrtc.org/2674243002
Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#16445}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: b114e9c159156a15c4998e37bc2af38920886cfa

Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk