pstore/ram: Move pmsg init earlier

Since the ftrace area can vary in size based on CPU count, move pmsg
initialization earlier so it will have a stable location.

Suggested-by: Paramjit Oberoi <pso@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-3-keescook@chromium.org

Author: kees

fs/pstore/ram.c

@@ -785,6 +785,11 @@ static int ramoops_probe(struct platform_device *pdev)
 	if (err)
 		goto fail_init;
 
+	err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
+				cxt->pmsg_size, 0);
+	if (err)
+		goto fail_init;
+
 	cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 				? nr_cpu_ids
 				: 1;
@@ -796,11 +801,6 @@ static int ramoops_probe(struct platform_device *pdev)
 	if (err)
 		goto fail_init;
 
-	err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
-				cxt->pmsg_size, 0);
-	if (err)
-		goto fail_init;
-
 	cxt->pstore.data = cxt;
 	/*
 	 * Prepare frontend flags based on which areas are initialized.