Initialize variables before usage.

Found by:	clang static analyzer
Found by:	Coverity Prevent[tm] (CID 7736, 7760)

sbin/camcontrol/modeedit.c

@@ -394,6 +394,7 @@ load_format(const char *pagedb_path, int page)
 
 	SLIST_INIT(&namelist);
 
+	c = '\0';
 	depth = 0;
 	lineno = 0;
 	found = 0;

sbin/gvinum/gvinum.c

@@ -644,6 +644,7 @@ gvinum_detach(int argc, char **argv)
 	struct gctl_req *req;
 	int flags, i;
 
+	flags = 0;
 	optreset = 1;
 	optind = 1;
 	while ((i = getopt(argc, argv, "f")) != -1) {