REGTESTS: use "command -v" instead of "which"

Ilya reported that the "which" utility is not that much portable and is
absent from Fedora. "type -p" is not portable either, and the correct
solution appears to be "command -v", so let's use this for now, we can
change it again in the future in case of problems.

Link: https://www.mail-archive.com/haproxy@formilux.org/msg36332.html
(cherry picked from commit b5e62679aaf1369b9a8f5604d8ab438e6bc70e2d)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 34a0c6399c67db858aa54401706765e0de72817e)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed