Correct rpm -ql exit value when optional -p is omitted (RhBug:1680610)

[pavlinamv]

Additionally if a package query with the argument was successful, there
is no need to rpm query of the argument.

[pavlinamv]

An additional commit is added for correcting -ql output for multiple rpm files if -p is omitted.
(Thus the PR does not exactly correspond to its name).

[pmatilai]

• Use rpmFileHasSuffix() instead of manual calculation (yes I know you're not adding the calculation, but might as well get rid of it while touching the code)
• Pretty please, no numbered variables unless the number is a meaningful part of the of the name (eg in coordinates x1, y1, x2, y2 are meaningful). If you can come up with a name/abbreviation that's actually meaningful to the context, great. If not, "xx" is commonly used these sort of internal, temporary error codes.

[pavlinamv]

I (hopefully) incorporated all comments from Florian and Panu. The line with a manual calculation is not a part of the 2 patches now. Thus I added the third patch to change it (on 2 places in the query file - to be consistent). If you think that the last commit should not be used, I am fine with it.

[pmatilai]

Merged, thanks.