Fix shellcheck detected errors

- onos-package
  SC2071: > is for string comparisons. Use -gt instead.

- ./tools/build/onos-blackduck-zip
  SC1035: You need a space after the [ and before the ].

Change-Id: I409b4a181e9cd49795afbdaa68b68c26413b9401
diff --git a/tools/build/onos-package b/tools/build/onos-package
index 1700b3c..18619da 100755
--- a/tools/build/onos-package
+++ b/tools/build/onos-package
@@ -204,7 +204,7 @@
 set -e
 
 [[ $# == 0 ]] && ONOS_PACKAGE_TAR_arg=true
-while [[ $# > 0 ]]; do
+while [[ $# -gt 0 ]]; do
 case $1 in
     -t|--tar)
         ONOS_PACKAGE_TAR_arg=true