efi_loader: missing return in efi_get_next_variable_name()

Add a missing return statement in efi_get_next_variable_name().

Reported-by: Coverity (CID 185834)
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index e0d7f57..699f418 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -335,7 +335,7 @@
 	EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, vendor);
 
 	if (!variable_name_size || !variable_name || !vendor)
-		EFI_EXIT(EFI_INVALID_PARAMETER);
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
 
 	if (variable_name[0]) {
 		/* check null-terminated string */