params.c: fix Smack complaint about parse_args

In commit 9fb48c74: "params: add 3rd arg to option handler callback
signature", the if-guard added to the pr_debug was overzealous; no
callers pass NULL, and existing code above and below the guard assumes
as much.  Change the if-guard to match, and silence the Smack
complaint.

CC: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/params.c

@@ -190,7 +190,7 @@ int parse_args(const char *doing,
 	/* Chew leading spaces */
 	args = skip_spaces(args);
 
-	if (args && *args)
+	if (*args)
 		pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
 
 	while (*args) {