fbdev: Support NULL for name in option-string lookup

Ignore the per-driver video options if no driver name has been
specified to fb_get_option(). Return the global options in this
case.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230209135509.7786-4-tzimmermann@suse.de

drivers/video/fbdev/core/fb_cmdline.c

@@ -39,13 +39,18 @@ int fb_get_options(const char *name, char **option)
 {
 	const char *options = NULL;
 	int retval = 0;
-	int name_len = strlen(name), i;
+	size_t name_len;
 	char *opt;
 
+	if (name)
+		name_len = strlen(name);
+
 	if (name_len && ofonly && strncmp(name, "offb", 4))
 		retval = 1;
 
 	if (name_len && !retval) {
+		unsigned int i;
+
 		for (i = 0; i < FB_MAX; i++) {
 			if (video_options[i] == NULL)
 				continue;