Merge bitcoin-core/secp256k1#1738: check-abi: remove support for obsolete CMake library output location (src/libsecp256k1.so)

7ebaa134a7 check-abi: remove support for obsolete CMake library output location (src/libsecp256k1.so) (Sebastian Falbesoner)

Pull request description:

  The CMake library output location was changed from "src/" to "lib/" in PR #1553, supporting the old location (presumably done to avoid having users to reconfigure existing CMake builds for a temporary transition window) shouldn't be necessary anymore.

ACKs for top commit:
  real-or-random:
    utACK 7ebaa134a7

Tree-SHA512: 7a4e86260d9593ba4616590c927ae8753b007d51426a86eeb6f8fa35338cfa6c9b05d962f32d0d84a3271340edff2cd50f9180ce1357ab49b7850b58fa017192

tools/check-abi.sh

@@ -49,14 +49,7 @@ checkout_and_build() {
         -DSECP256K1_BUILD_CTIME_TESTS=OFF \
         -DSECP256K1_BUILD_EXAMPLES=OFF
     cmake --build . -j "$(nproc)"
-    # FIXME: Just set LIBPATH to lib/libsecp256k1.so once version 0.6.0 is
-    # released.
-    if [ -f "src/libsecp256k1.so" ]; then
-        LIBPATH="src/libsecp256k1.so"
-    else
-        LIBPATH="lib/libsecp256k1.so"
-    fi
-    abi-dumper $LIBPATH -o ABI.dump -lver "$2" -public-headers ../include/
+    abi-dumper lib/libsecp256k1.so -o ABI.dump -lver "$2" -public-headers ../include/
     cd "$_orig_dir"
 }