drm/nouveau/debugfs: Use seq_putc() in nouveau_debugfs_pstate_get()

A single character (line break) should be put into a sequence.
Thus use the corresponding function “seq_putc”.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e6f9b34e-58d9-b1aa-8b12-8d4a55153d1d@web.de

drivers/gpu/drm/nouveau/nouveau_debugfs.c

@@ -132,7 +132,7 @@ nouveau_debugfs_pstate_get(struct seq_file *m, void *data)
 				seq_printf(m, " DC");
 		}
 
-		seq_printf(m, "\n");
+		seq_putc(m, '\n');
 	}
 
 	return 0;