kdumpst-load: Guard initrd creation against failures

Though rare, they might happen and then journal show non-handled
errors - better sanitize a bit the message.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>

kdumpst-load.sh.in

@@ -214,6 +214,12 @@ fi
 INITRD_FNAME="${MOUNT_FOLDER}/kdump-initrd-$(uname -r).img"
 if [ ! -s "${INITRD_FNAME}" ]; then
 	create_initrd
+
+	#  Check if create_initrd() succeeded.
+	if [ ! -s "${INITRD_FNAME}" ]; then
+		logger "kdumpst: failure on initrd creation - aborting."
+		exit 1
+	fi
 fi
 
 if ! kexec -s -p "${VMLINUX}" --initrd "${INITRD_FNAME}" --append="${KDUMP_CMDLINE}"; then