kernel-install: fix BLS-related decision logic

In the commit 63205a4dc4c400f75571869d87682c0cdb475830, there was
introduced a change in the decision logic of the 20-zipl-kernel.install
script. Specifically, whether the Boot Loader Specification (BLS) is
used. Instead of just checking the existence of the /sbin/new-kernel-pkg
file, the existence of the /boot/loader/entries directory is also
checked.

More thorough testing revealed that the above commit covers only the
case when a new kernel is added. However, the remaining cases should
also be covered. That means the case when a rescue kernel is added and
the case when some kernel is removed.

Resolves: #1778243
Fixes: #1755899

Signed-off-by: Jan Hlavac <jhlavac@redhat.com>

20-zipl-kernel.install

@@ -74,7 +74,7 @@ case "$COMMAND" in
             fi
         fi
 
-        if [[ ! -f /sbin/new-kernel-pkg || -d "$BLS_DIR" ]]; then
+        if [[ ! -f /sbin/new-kernel-pkg || -d "${BLS_DIR}" ]]; then
             declare -a BOOT_OPTIONS
             if [[ -f /etc/kernel/cmdline ]]; then
                 read -r -d '' -a BOOT_OPTIONS < /etc/kernel/cmdline
@@ -146,7 +146,7 @@ case "$COMMAND" in
         exit 77
         ;;
     remove)
-        if [[ ! -f /sbin/new-kernel-pkg ]]; then
+        if [[ ! -f /sbin/new-kernel-pkg || -d "${BLS_DIR}" ]]; then
             ARCH="$(uname -m)"
             BLS_TARGET="${BLS_DIR}/${MACHINE_ID}-${KERNEL_VERSION}.conf"
             BLS_DEBUG="$(echo ${BLS_TARGET} | sed -e "s/${KERNEL_VERSION}/${KERNEL_VERSION}~debug/")"

52-zipl-rescue.install

@@ -15,7 +15,7 @@ BLS_DIR="/boot/loader/entries"
 [[ "$KERNEL_VERSION" == *\+* ]] && flavor=-"${KERNEL_VERSION##*+}"
 case "$COMMAND" in
     add)
-        if [[ ! -f /sbin/new-kernel-pkg ]]; then
+        if [[ ! -f /sbin/new-kernel-pkg || -d "${BLS_DIR}" ]]; then
             declare -a BOOT_OPTIONS
             if [[ -f /etc/kernel/cmdline ]]; then
                 read -r -d '' -a BOOT_OPTIONS < /etc/kernel/cmdline