Updated Nmap build script

Author: takeshixx

build/targets/build_nmap.sh

@@ -1,12 +1,16 @@
 #!/bin/bash
-set -e
-set -x
-set -o pipefail
+if [ -z "$GITHUB_WORKSPACE" ];then
+    echo "GITHUB_WORKSPACE environemnt variable not set!"
+    exit 1
+fi
 if [ "$#" -ne 1 ];then
     echo "Usage: ${0} [x86|x86_64|armhf|aarch64]"
     echo "Example: ${0} x86_64"
     exit 1
 fi
+set -e
+set -o pipefail
+set -x
 source $GITHUB_WORKSPACE/build/lib.sh
 init_lib $1