display_feature_log if found

[Yury G. Kudryashov]

Hi!

Sometimes I see

m_o_f_p(Foo) # or find_package(Foo)
if (NOT Foo_FOUND)
display_feature_log(...)
endif (NOT Foo_FOUND)

In this case nothing is displayed when dependency is found. It looks strange 
to me, and I'd like to remove these if..endif.

I'm new to KDE buildsystem, so I prefer to ask before commiting.