[PATCH v1 15/18] website-build: serve.sh: help: fix program name.

[Denis 'GNUtoo' Carikli]

The GNU Coding Standards has the following in the chapter "4.8.1
--version"[1]:
    The program’s name should be a constant string; don’t compute it
    from argv[0]. The idea is to state the standard or canonical name
    for the program, not its file name. There are other ways to find
    out the precise file name where a command is found in PATH.
[1]https://www.gnu.org/prep/standards/standards.html#g_t_002d_002dversion

This fixes that.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
 website-build/serve.sh | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/website-build/serve.sh b/website-build/serve.sh
index a826c69..8b53545 100755
--- a/website-build/serve.sh
+++ b/website-build/serve.sh
@@ -18,12 +18,14 @@ set -e
 
 usage()
 {
-       echo "$0 <path/to/tarball> [PORT]"
+       progname="$1"
+
+       echo "${progname} <path/to/tarball> [PORT]"
        exit 1
 }
 
 if [ $# -ne 1 ] && [ $# -ne 2 ] ; then
-       usage
+       usage "serve.sh"
 fi
 
 basedir="$(dirname $(realpath $0))"
-- 
2.41.0