Change in flashrom[master]: cli_classic: Make -r/-w/-v argument optional

[Edward O'Callaghan (Code Review)]

Attention is currently required from: Nico Huber, Angel Pons, Daniel Campello.
Edward O'Callaghan has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/52362 )

Change subject: cli_classic: Make -r/-w/-v argument optional
......................................................................

Patch Set 1: Code-Review+2

(4 comments)

File cli_classic.c:

https://review.coreboot.org/c/flashrom/+/52362/comment/f3874057_6b03ab9d 
PS1, Line 140: static char *get_optional_filename(char *argv[])
Can you leave a comment on this function what precisely it is expected to do here. Longer term as the flashrom team here works on improving unit-test coverage I guess things like this are nice candidates for folks to get started with. Therefore comments help them form the right tests.

I left some comments in flashrom.c with the diff with how the chromiumos tree behaves with the file descriptors when the user doesn't specify them. I was wondering if you can speak to that diff more so that we can close the gap off there once this lands?

File flashrom.c:

https://review.coreboot.org/c/flashrom/+/52362/comment/4beaa0f6_50ea259d 
PS1, Line 1351: 	if ((image = fopen(filename, "rb")) == NULL) {
```
-       if (!strncmp(filename, "-", sizeof("-")))
-               image = fdopen(STDIN_FILENO, "rb");
-       else
-               image = fopen(filename, "rb");
-       if (image == NULL) {
+       if ((image = fopen(filename, "rb")) == NULL) {
```

https://review.coreboot.org/c/flashrom/+/52362/comment/1f3c9283_663aa16f 
PS1, Line 1361: 
              : 	if (image_stat.st_size != (intmax_t)size) {
```
-       if ((image_stat.st_size != (__off_t)size) &&
-           (strncmp(filename, "-", sizeof("-")))) {
+       if (image_stat.st_size != (intmax_t)size) {
```

https://review.coreboot.org/c/flashrom/+/52362/comment/871adb21_c9c6dd74 
PS1, Line 1439: 	if ((image = fopen(filename, "wb")) == NULL) {
```
-       if (!strncmp(filename, "-", sizeof("-")))
-               image = fdopen(STDOUT_FILENO, "wb");
-       else
-               image = fopen(filename, "wb");
-       if (image == NULL) {
+       if ((image = fopen(filename, "wb")) == NULL) {
```