Fix sed portability issue

- -i without extension for backup is not portable
- -E is not portable, removed (ERE not required in this regexp)

Change-Id: I215949415baa5932ceefb1a83a577990ce068a58
diff --git a/tools/build/onos-buck-publish b/tools/build/onos-buck-publish
index 24ce932..aa56dea 100755
--- a/tools/build/onos-buck-publish
+++ b/tools/build/onos-buck-publish
@@ -22,7 +22,7 @@
 onos-buck query "filter('.*-oar', deps('//tools/package:onos-package', 1))" >> $ARTIFACT_PUB
 echo "//tools/package:onos-features" >> $ARTIFACT_PUB
 
-sed -i "" -E 's/^/onos-buck publish --to-maven-central --include-source --include-javadoc --sign /g' $ARTIFACT_PUB
+sed -i.bak 's/^/onos-buck publish --to-maven-central --include-source --include-javadoc --sign /g' $ARTIFACT_PUB
 
 # Print commands to be run and then run them
 cat $ARTIFACT_PUB
@@ -30,11 +30,11 @@
 
 # Prepare test publish commands
 onos-buck query "testsof(kind('onos_jar', deps('//tools/package:onos-package')))" >> $TEST_PUB
-sed -i "" -E 's#^#onos-buck publish --to-maven-central --sign #g' $TEST_PUB
+sed -i.bak 's#^#onos-buck publish --to-maven-central --sign #g' $TEST_PUB
 
 # Print commands to be run and then run them
 cat $TEST_PUB
 bash $TEST_PUB
 
 # Close the staging area
-onos-close-staging
\ No newline at end of file
+onos-close-staging