rmtfs: Fix command line argument parsing for '-o' optarg

Commit 2ee01bf ("storage: Try opening the slot-suffixed partition")
introduced a bug where option '-o' is incorrectly specified as having no
argument. Therefore, passing -o with a path incorrectly sets that path
to the default '/boot' one as optarg evaluates to NULL. Fix this by
telling getopt that we expect an argument.

Fixes: 2ee01bf ("storage: Try opening the slot-suffixed partition")
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>

Author: qzed

rmtfs.c

@@ -505,7 +505,7 @@ int main(int argc, char **argv)
 	int option;
 	const char *storage_root = NULL;
 
-	while ((option = getopt(argc, argv, "oS:Prsv")) != -1) {
+	while ((option = getopt(argc, argv, "o:S:Prsv")) != -1) {
 		switch (option) {
 		/*
 		 * -o sets the directory where EFS images are stored,