s390/debug: avoid kernel warning on too large number of pages

When specifying insanely large debug buffers a kernel warning is
printed. The debug code does handle the error gracefully, though.
Instead of duplicating the check let us silence the warning to
avoid crashes when panic_on_warn is used.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

arch/s390/kernel/debug.c

@@ -198,9 +198,10 @@ static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas)
 	if (!areas)
 		goto fail_malloc_areas;
 	for (i = 0; i < nr_areas; i++) {
+		/* GFP_NOWARN to avoid user triggerable WARN, we handle fails */
 		areas[i] = kmalloc_array(pages_per_area,
 					 sizeof(debug_entry_t *),
-					 GFP_KERNEL);
+					 GFP_KERNEL | __GFP_NOWARN);
 		if (!areas[i])
 			goto fail_malloc_areas2;
 		for (j = 0; j < pages_per_area; j++) {