open-coredump: do not assume remote repo name

open-coredump.sh allows us to specify --scylla-repo-path, but
developer's remote repo name is not always "origin" -- the
"origin" could be his/her own remote repo. not the one from which
we want to pull from.

so, in this change, assuming that the remote repo to be pulled
from has been added to the local repo, we query the local repo
for its name and pull using that name instead.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes #15220

scripts/open-coredump.sh

@@ -283,13 +283,15 @@ if ! [[ -d ${SCYLLA_REPO_PATH} ]]
 then
     log "Cloning ${PRODUCT}.git"
     git clone ${GIT_QUIET_FLAG} -b ${BRANCH} git@github.com:scylladb/${PRODUCT}.git ${SCYLLA_REPO_PATH}
+    REMOTE_REPO_NAME=origin
 else
     log "${PRODUCT}.git already cloned"
+    REMOTE_REPO_NAME=$(cd ${SCYLLA_REPO_PATH}; git remote -v | awk "/scylladb\/${PRODUCT}.*fetch/{ print \$1 }")
 fi
 
 # We do the checkout unconditionally, it is cheap anyway.
 pushd ${SCYLLA_REPO_PATH} > /dev/null
-git fetch -q origin ${BRANCH}
+git fetch -q ${REMOTE_REPO_NAME} ${BRANCH}
 git checkout -q ${COMMIT_HASH}
 # Skip the other submodules, they are not needed for debugging
 git submodule -q sync
@@ -310,7 +312,7 @@ then
         WORKDIR=$(pwd)
         cd ${SCYLLA_REPO_PATH}
         git checkout -q $MAIN_BRANCH
-        git pull -q --no-recurse-submodules origin $MAIN_BRANCH
+        git pull -q --no-recurse-submodules ${REMOTE_REPO_NAME} $MAIN_BRANCH
         log "Copying scylla-gdb.py from ${SCYLLA_REPO_PATH}"
         cp scylla-gdb.py ${WORKDIR}/scylla-gdb.py
         git checkout -q ${COMMIT_HASH}