fix shellcheck findings based on eficode/pull/16

wait-for

@@ -31,7 +31,7 @@ usage() {
   exitcode="$1"
   cat << USAGE >&2
 Usage:
-  $(basename $0) [host:port...] [-t timeout] [-- command args]
+  $(basename "$0") [host:port...] [-t timeout] [-- command args]
   -q | --quiet                        Do not output any status messages
   -l | --loose                        Execute subcommand even if the test times out
   -t TIMEOUT | --timeout=timeout      Timeout in seconds, zero for no timeout
@@ -54,15 +54,15 @@ test_connection() {
 
 wait_for() {
   local result
-  for i in `seq $TIMEOUT` ; do
+  for _ in $(seq $TIMEOUT) ; do
     # use a 1-second timeout, but still sleep 0.1 seconds after just to be safe
     test_connection "$1" "$2"
     result=$?
     if [ $result -eq 0 ] ; then break ; fi
     sleep 1
   done
   [ $result -ne 0 ] && echoerr "Operation timed out waiting for $1:$2"
-  if [ $result -eq 0 -o $LOOSE -eq 1 -a $# -gt 0 ] ; then
+  if [ $result -eq 0  ] || [ $LOOSE -eq 1  ] && [ $# -gt 0 ] ; then
     TIMEOUT=$OLD_TIMEOUT QUIET=$OLD_QUIET PORT=$OLD_PORT HOST=$OLD_HOST LOOSE=$OLD_LOOSE exec "$@"
   fi
   exit $result
@@ -117,7 +117,7 @@ for SERVICE in ${SERVICES} ; do
 	HOST=$(printf "%s\n" "$SERVICE"| cut -d : -f 1)
 	PORT=$(printf "%s\n" "$SERVICE"| cut -d : -f 2)
 
-	if [ "$HOST" = "" -o "$PORT" = "" ]; then
+	if [ "$HOST" = "" ] || [ "$PORT" = "" ]; then
   	echoerr "Error: you need to provide a host and port to test."
   	usage 2
 	fi