Correct shell script linting

The use of shellcheck was recently merged which has noted a few issues
with the `bootstrap.sh` script used to clean and configure the fan
applications. This did not cause an error in the `format-code.sh` check
since there's no `.shellcheck` file, however it still showed the issues
during unit test runs.

Change-Id: I3973112f4839afc6ea81863c2c54100e680bb260
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/bootstrap.sh b/bootstrap.sh
index 8aae0ef..52ec8f1 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -8,11 +8,11 @@
     clean)
         test -f Makefile && make maintainer-clean
         for file in ${AUTOCONF_FILES}; do
-            find -name "$file" | xargs -r rm -rf
+            find . -name "$file" -exec rm -rf {} +
         done
         exit 0
         ;;
 esac
 
 autoreconf -if
-echo 'Run "./configure ${CONFIGURE_FLAGS} && make"'
+echo "Run \"./configure \${CONFIGURE_FLAGS} && make\""