[testsuite] Remove bashism from libbacktrace/allocfail.sh

Test-case libbacktrace/allocfail.sh contains bashism "set -o pipefail", which
makes the script fail on ubuntu 18.04, which links /bin/sh to /bin/dash.

Fix this by removing the "set -o pipefail".

Tested by running the test-case with dash on x86_64-linux.

2018-12-14  Tom de Vries  <tdevries@suse.de>

	PR testsuite/88491
	* allocfail.sh: Remove "set -o pipefail".

From-SVN: r267127

libbacktrace/ChangeLog

+2018-12-14  Tom de Vries  <tdevries@suse.de>
+
+	PR testsuite/88491
+	* allocfail.sh: Remove "set -o pipefail".
+
 2018-12-12  Tom de Vries  <tdevries@suse.de>
 
 	* Makefile.am (TESTS): Add allocfail.sh.

libbacktrace/allocfail.sh

@@ -32,7 +32,6 @@
 # POSSIBILITY OF SUCH DAMAGE.
 
 set -e
-set -o pipefail
 
 if [ ! -f ./allocfail ]; then
     # Hard failure.