NetEq: Removing two asserts

These asserts cover error cases that are also handled by the code
after the assert. Should not have both assert and error handling.

BUG=webrtc:4840

Review URL: https://codereview.webrtc.org/1321023002

Cr-Original-Commit-Position: refs/heads/master@{#9804}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 98f3cc54daf0385e8b76875aa4ea0cb16987bfc5
1 file changed