Fix --noheader on fw_printenv

The single argument `--noheader' is expecting isn't taken from getopt
parsing, but instead from the remaining argv arguments.

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
diff --git a/tools/env/fw_env_main.c b/tools/env/fw_env_main.c
index 6fdf41c..d93a915 100644
--- a/tools/env/fw_env_main.c
+++ b/tools/env/fw_env_main.c
@@ -46,7 +46,7 @@
 	{"config", required_argument, NULL, 'c'},
 	{"help", no_argument, NULL, 'h'},
 	{"script", required_argument, NULL, 's'},
-	{"noheader", required_argument, NULL, 'n'},
+	{"noheader", no_argument, NULL, 'n'},
 	{"lock", required_argument, NULL, 'l'},
 	{"version", no_argument, NULL, 'v'},
 	{NULL, 0, NULL, 0}