shellcheck fixes

Signed-off-by: Jesse Vincent <jesse@keyboard.io>

bin/kaleidoscope-builder

@@ -47,15 +47,15 @@ build_filenames () {
 
 
 enable_ccache () {
-    if  [ `which ccache` ]; then
+    if  [ $(which ccache) ]; then
     if ! [ -d $CCACHE_WRAPPER_DIR ]; then
 	mkdir -p $CCACHE_WRAPPER_DIR
-	ln -s `which ccache` ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}gcc
-	ln -s `which ccache` ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}g++
-	ln -s ${AVR_NM} ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}nm
-	ln -s ${AVR_OBJCOPY} ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}objcopy
-	ln -s ${AVR_AR} ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}ar
-	ln -s ${AVR_SIZE} ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}size
+	ln -s "$(which ccache)" ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}gcc
+	ln -s "$(which ccache)" ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}g++
+	ln -s "${AVR_NM}" ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}nm
+	ln -s "${AVR_OBJCOPY}" ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}objcopy
+	ln -s "${AVR_AR}" ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}ar
+	ln -s "${AVR_SIZE}" ${CCACHE_WRAPPER_DIR}/${COMPILER_PREFIX}size
     fi
     export CCACHE_PATH=${COMPILER_PATH}/
     CCACHE_ENABLE="-prefs compiler.path=${CCACHE_WRAPPER_DIR}/"