Change Linux Makefile to match the Windows and Mac ones

[Jojo-Schmitz]

follow up for PR #5928 and just for consistency

[AntonioBL]

You need a double space between "VERSION" and "*",
so that ^.*VERSION * (I can't insert the double space with the markup of comments, imagine there are two spaces here) matches the line starting with whatever number of (any) characters ("^.*"), contains "VERSION " (note the space) and then has whatever number of other spaces (" *", this number can also be 0) before the piece we want to obtain. Otherwise it takes the wrong line in the config file.

[Jojo-Schmitz]

Thanks, you are of course right:

Jojo@QuadCore MSYS ~/Documents/GitHub/MuseScore (build)
$ cmake -P config.cmake | sed -n -e "s/^.*VERSION *//p"
_FULL 3.5.0
3.5b-0950eca

Jojo@QuadCore MSYS ~/Documents/GitHub/MuseScore (build)
$ cmake -P config.cmake | sed -n -e "s/^.*VERSION  *//p"
3.5b-0950eca

Fixed. Seems my Copy/Paste went wrong earlier somehow, probably for the same reason as you couldn't show a double space in your comment ;-)

[shoogle]

Doesn't matter too much here, but generally it's better to use := than = for assignment and $(shell <cmd>) rather than backticks. See https://stackoverflow.com/a/1435867

[Jojo-Schmitz]

I like that much better. Works with GNU make only though. Not sure we can take that for granted everywhere?

[shoogle]

It's already used to set CPUS a few lines above and nobody has complained yet.

[Jojo-Schmitz]

Sure, for Linux (and I guess *BSD too). For Windows/MinGW most probably too, not so sure about Mac though?
Well, just let's do it ;-)