ncm-spma: improve yum locked_all_packges message logging

fixes #376
These identifiers are too long for such a short function. I'm all in for meaningful names, but this actually clutters the string interpolation below, highlighting the trees and hiding the forest.

```perl
my ($wanted_locked, $unmatched) = @_:

my $nw = $wanted_locked->size();
my $nu = scalar(@$unmatched);
...
```