Fix shellcheck

scripts/circleci/buckToJunit/buckToJunit.sh

@@ -1,24 +1,25 @@
 #!/bin/bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
 
 # Get script directory
 prog="$0"
 while [ -h "${prog}" ]; do
-    newProg=`/bin/ls -ld "${prog}"`
-    newProg=`expr "${newProg}" : ".* -> \(.*\)$"`
+    newProg=$(/bin/ls -ld "${prog}")
+    newProg=$(expr "${newProg}" : ".* -> \(.*\)$")
     if expr "x${newProg}" : 'x/' >/dev/null; then
         prog="${newProg}"
     else
-        progdir=`dirname "${prog}"`
+        progdir=$(dirname "${prog}")
         prog="${progdir}/${newProg}"
     fi
 done
-DIR=`dirname $prog`
+DIR=$(dirname "${prog}")
 
 # We download saxon from Maven Central rather than copying it over.
-curl https://repo1.maven.org/maven2/net/sf/saxon/Saxon-HE/9.7.0-11/Saxon-HE-9.7.0-11.jar --output $DIR/saxon.jar
-
-saxonJar="$DIR/saxon.jar"
-buckToJunitXsl="$DIR/buckToJunit.xsl"
+curl https://repo1.maven.org/maven2/net/sf/saxon/Saxon-HE/9.7.0-11/Saxon-HE-9.7.0-11.jar --output "$DIR/saxon.jar"
 
 # Perform conversion
-java -jar $saxonJar -xsl:$buckToJunitXsl -s:$1 -o:$2
+java -jar "$DIR/saxon.jar" -xsl:"$DIR/buckToJunit.xsl" -s:"$1" -o:"$2"