Fix scripts when launching from bin

When running a script that depends on elasticsearch-env, the
elasticsearch-env script seeks backwards from the directory containing
the script to find Elasticsearch home. This is done by seeking backwards
in the path to find bin, and then going one directory above
that. Unfortunately, if the script is started relatively from the bin
directory, then bin will appear in the path since it is a relative
path. This commit fixes this by making the starting path absolute before
attempting to seek backwards.

distribution/src/main/resources/bin/elasticsearch-env

@@ -21,14 +21,15 @@ done
 # bin, and then strip bin (there is an assumption here that there is no nested
 # directory under bin also named bin)
 ES_HOME=`dirname "$SCRIPT"`
+
+# now make ES_HOME absolute
+ES_HOME=`cd "$ES_HOME"; pwd`
+
 while [ "`basename "$ES_HOME"`" != "bin" ]; do
   ES_HOME=`dirname "$ES_HOME"`
 done
 ES_HOME=`dirname "$ES_HOME"`
 
-# now make ES_HOME absolute
-ES_HOME=`cd "$ES_HOME"; pwd`
-
 # now set the classpath
 ES_CLASSPATH="$ES_HOME/lib/*"