[PATCH] xrow: improve corrupted header logging on an error

[Vladimir Davydov]

On Fri, Apr 05, 2019 at 07:09:17PM +0300, Serge Petrenko wrote:
> Improve row printing to log. Since say only has 16k buffer, there is no
> point in printing the whole packet, which can have arbitrary length, in one
> go.
> So, print the header row by row, 16 bytes in a row, and format output to
> match `xxd` output:
> ```
> [001] 2019-04-05 18:22:46.679 [11859] iproto V> Got a corrupted row:
> [001] 2019-04-05 18:22:46.679 [11859] iproto V> 00000000: A3 02 D6 5A E4 D9 E7 68 A1 53 8D 53 60 5F 20 3F
> [001] 2019-04-05 18:22:46.679 [11859] iproto V> 00000010: D8 E2 D6 E2 A3 02 D6 5A E4 D9 E7 68 A1 53 8D 53
> ```
> Now we can get rid of malloc, and use a preallocated tt_static_buf
> instead.
> Also, replace a big macro with a small macro and a helper function.

Looks awesome, thanks! Pushed to master, 2.1, and 1.10.

It's a shame we didn't think about multiline output ourselves until
Kostja suggested it :(