fadump: avoid status check while starting in fadump mode

With kernel commit 607451ce0aa9b ("powerpc/fadump: register for fadump
as early as possible"), 'kdumpctl start' prematurely returns with the
below message:

    "Kdump already running: [WARNING]"

instead of setting default initrd with dump capture capability as
required for fadump. Skip status check in fadump mode to avoid this
problem.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>

kdumpctl

@@ -1061,7 +1061,7 @@ start()
 		return 1
 	fi
 
-	if check_current_status; then
+	if [[ $DEFAULT_DUMP_MODE == "kdump" ]] && check_current_kdump_status; then
 		dwarn "Kdump already running: [WARNING]"
 		return 0
 	fi