abi/bootstrap: update libabigail to current master

Until a release (1.7) has been published upstream, we need to build and
use a trunk version of libabigail as we make use of recent
functionality only available in master.

Hence, pin down the libabigail version to a sufficient master commit [1].

[1] https://sourceware.org/git/?p=libabigail.git;a=commit;h=fb70149cb1bacb62209180d5ee59ba7022c7ec85

Change-Id: I6f0527d2d85e5c85690d2f83fa9379ae65ee9ab2
Signed-off-by: Matthias Maennich <maennich@google.com>
diff --git a/abi/bootstrap b/abi/bootstrap
index bac3c73..dace036 100755
--- a/abi/bootstrap
+++ b/abi/bootstrap
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ABIGAIL_VERSION=1.6
+ABIGAIL_VERSION=fb70149c
 
 NUM_CORES=$(cat /proc/cpuinfo | grep -c proc)
 BASE_DIR=$(readlink -f $(dirname $0))
@@ -48,7 +48,7 @@
   git -C ${LIBABIGAIL_SRC} fetch
 fi
 
-git -C ${LIBABIGAIL_SRC} checkout libabigail-${ABIGAIL_VERSION}
+git -C ${LIBABIGAIL_SRC} checkout ${ABIGAIL_VERSION}
 
 # Build libabigail
 pushd "${LIBABIGAIL_SRC}"