fix(xcat-core): retry_install defaults to 2 provision attempts, not 3

retry_install.sh retries a node provision $times (default 3) x 30 min. The flat
diskless/diskfull cases each call it multiple times, so when a node genuinely
fails to come up the retries stack to ~3.5-4 h per case (measured: a single
contention-flaked el8-x86 diskless burned 14181s in devel-cd #22), which both
balloons the CD wall-clock and delays the red verdict.

Two attempts still absorbs a one-off transient (a single slow/failed netboot)
while halving the worst-case retry time (3->2 tries per call). Callers that pass
an explicit count (e.g. the negative-provision check that passes 1) are
unaffected -- only the default changes.

Signed-off-by: Daniel Hilst <392820+dhilst@users.noreply.github.com>
(cherry picked from commit b9336448f7)

xCAT-test/autotest/testcase/commoncmd/retry_install.sh

@@ -6,7 +6,7 @@ declare -i tryreinstall=1
 node=$1
 osimage=$2
 vmhost=`lsdef $node -i vmhost -c | cut -d '=' -f 2`
-times=3
+times=2
 wait_for_provision=30 #Min to wait for node to provision
 check_status=10 #Sec to keep checking status
 iterations=$wait_for_provision*60/$check_status #Iterations to check for "booted" status