efi_convert_cmdline() always returns a size of at least 1 because it counts
the NUL terminator, so the "cmdline_size == 0" condition is not possible.

Change it to check if the string starts with a NUL character to get the
intended behavior: to use CONFIG_CMDLINE when load_options_size is 0.

Fixes: 60f38de7a8d4 ("efi/libstub: Unify command line param parsing")
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
---
 drivers/firmware/efi/libstub/efi-stub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 958a680e0660d..2a1b43f9e0fa2 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -129,7 +129,7 @@ efi_status_t efi_handle_cmdline(efi_loaded_image_t *image, char **cmdline_ptr)
 
 	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
 	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
-	    cmdline_size == 0) {
+	    cmdline[0] == 0) {
 		status = efi_parse_options(CONFIG_CMDLINE);
 		if (status != EFI_SUCCESS) {
 			efi_err("Failed to parse options\n");
-- 
2.45.1