linux.rs: add clippy allow for manual_map
linux.rs: add clippy allow for manual_map

This only triggers when the powerd support is compiled out, so just
ignore it.

While we're here, fix the name of the power-monitor-powerd feature in
the line just below (drop the extra "d"); it would always apply, since
the feature name was misspelled.

BUG=b:197251702
TEST=bin/clippy # with rust-toolchain = 1.54.0

Change-Id: I1b8ef3732c3d5968a9e230216f8f727bd1445609
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3108612
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Commit-Queue: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Reviewed-by: Allen Webb <880184b418addffb87cd9c8e8e882ca6764ac96b@google.com>

google/crosvm,google/crosvm,google/crosvm,google/crosvm