[L] Change in flashrom[main]: Complete and fix progress feature implementation for all operations

[Sergii Dmytruk (Code Review)]

Attention is currently required from: Aarya, Anastasia Klimchuk, Nikolai Artemiev.

Sergii Dmytruk has posted comments on this change by Sergii Dmytruk. ( https://review.coreboot.org/c/flashrom/+/84102?usp=email )

Change subject: Complete and fix progress feature implementation for all operations
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Patch Set 11:

(1 comment)

File cli_output.c:

https://review.coreboot.org/c/flashrom/+/84102/comment/fcb62a6e_f9160390?usp... :
PS9, Line 164: 		progress_separator = (fmt[strlen(fmt) - 1] == '\n' ? NEWLINE : MIDLINE);
> Oh yes, I haven't thought about it! There are probably many ways to fix that, I picked one way, let  […]

I don't think it's worth calling `strlen()` twice like that in case of lots of logging lines.  Also if the format is empty, the state shouldn't change at all.  Maybe make a function like this to also reduce duplication:
```c
static void update_line_state(const char *fmt)
{
    size_t len = strlen(fmt);
    if (len != 0)
        line_state = (fmt[len - 1] == '\n' ? NEWLINE : MIDLINE);
}
```