Fail script on compilation error.

- Fail on any error in the build script to catch build issue earlier.

Change-Id: I951f61ad76096a3733224a97047abb56af029e97
diff --git a/ramcloud-build-scripts/build_jni_so.sh b/ramcloud-build-scripts/build_jni_so.sh
index a674e7f..e549e6a 100755
--- a/ramcloud-build-scripts/build_jni_so.sh
+++ b/ramcloud-build-scripts/build_jni_so.sh
@@ -1,5 +1,8 @@
 #!/bin/bash
 
+# fail on command error
+set -e
+
 JAVA_HOME=${JAVA_HOME:-/usr/lib/jvm/java-7-oracle}
 ONOS_HOME=${ONOS_HOME:-~/ONOS}
 RAMCLOUD_HOME=${RAMCLOUD_HOME:-~/ramcloud}
@@ -11,5 +14,4 @@
 
 g++ -g -Wall -O3 -shared -fPIC -std=c++0x -I${JAVA_HOME}/include/ -I${JAVA_HOME}/include/linux -I${RAMCLOUD_HOME}/src/ -I${RAMCLOUD_HOME}/obj.${RAMCLOUD_BRANCH}/ -I${RAMCLOUD_HOME}/logcabin/ -I${RAMCLOUD_HOME}/gtest/include/ -L${RAMCLOUD_HOME}/obj.${RAMCLOUD_BRANCH} -o ${ONOS_HOME}/lib/libedu_stanford_ramcloud_JRamCloud.so ${ONOS_HOME}/src/main/cpp/edu_stanford_ramcloud_JRamCloud.cc -lramcloud
 
-#ln -sf `pwd`/libedu_stanford_ramcloud_JRamCloud.so ${RAMCLOUD_HOME}/obj.${RAMCLOUD_BRANCH}