travis: split valgrind check in its own script

(cherry picked from commit 74b0a432)

.travis.yml

@@ -66,10 +66,7 @@ install:
 script:
  - script/cibuild.sh
  - script/citest.sh
-
-# Run Tests
-after_success:
- - if [ "$TRAVIS_OS_NAME" = "linux" -a -n "$VALGRIND" ]; then valgrind --leak-check=full --show-reachable=yes --suppressions=./libgit2_clar.supp _build/libgit2_clar -ionline; fi
+ - script/cileaks.sh
 
 # Only watch the development and master branches
 branches:

script/cileaks.sh

+#!/bin/sh
+
+set -x
+
+# If this platform doesn't support test execution, bail out now
+if [ -n "$SKIP_TESTS" ];
+then
+	exit $?;
+fi
+
+if [ -n "$VALGRIND" -a -e "$(which valgrind)" ]; then
+	valgrind --leak-check=full --show-reachable=yes --error-exitcode=125 --suppressions=./libgit2_clar.supp _build/libgit2_clar $@ -ionline
+fi