Use the correct type in the option parser struct

Change-Id: I3a03e80b4f7a096fc496066e3594a58fa1a6473f

src/wsman.c

diff --git a/src/wsman.c b/src/wsman.c
index 0edef89..f42dd34 100644
--- a/src/wsman.c
+++ b/src/wsman.c
@@ -224,7 +224,7 @@
 		{"prop", 'k', U_OPTION_ARG_STRING_ARRAY, &properties,
 			"Properties with key value pairs (For 'put', 'invoke' and 'create')",
 			"<key=val>"},
-		{"option", NULL, U_OPTION_ARG_STRING_ARRAY, &option_set_values,
+               {"option", 0, U_OPTION_ARG_STRING_ARRAY, &option_set_values,
 			"Option with key value pair for OptionSet (For 'put', 'invoke' and 'create')",
 			"<key=val>"},
 		{"config-file", 'C', U_OPTION_ARG_STRING, &config_file,