Remove type for mem* and str* symbols in riscv64 libc ABI dump am: 6b7f2c68ff am: 5df3e1c7c0

Original change: https://android-review.googlesource.com/c/platform/prebuilts/abi-dumps/ndk/+/2832454

Change-Id: Ie0158504dda35902afb232ded29ab0d9d2c6b086
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>