cmd: correct return value for printenv -e

If printenv -e is executed and the specified variable is not found, the
return value $? of the command should be 1 (false).

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/cmd/nvedit_efi.c b/cmd/nvedit_efi.c
index 7ebb14e..770877c 100644
--- a/cmd/nvedit_efi.c
+++ b/cmd/nvedit_efi.c
@@ -182,8 +182,10 @@
 	}
 	free(var_name16);
 
-	if (!match && argc == 1)
+	if (!match && argc == 1) {
 		printf("Error: \"%s\" not defined\n", argv[0]);
+		return CMD_RET_FAILURE;
+	}
 
 	return CMD_RET_SUCCESS;
 }