adb: Drop the unneeded dependency on libfec_rs.so.

It was only needed when we statically linked libfec into libadbd in
past.

Test: `mmma -j system/core/adb`
Test: `m -j installclean && m -j bootimage` with aosp_taimen-userdebug.
      Check the installed files in recovery image.
Change-Id: I8627d5f98568ab1d71e6a47cb1b2540a33bffdab