When the libsecret credential helper was split out in 9d91bab (split
libsecret credential helper into a subpackage (#1804741), 2020-02-19), a
few rpmlint errors & warnings crept in.
Update the rpmlintrc file to ignore the no-documentation warning for the
libsecret subpackage (replacing the gnome-keyring entry which is no
longer needed). Fix an errant tab added to the spec file.
Moving the libsecret credential helper to a subpackage left no binaries
in the main git package, so rpmlint complains. Fixing this requires a
bit more investigation and care.
Replace NO_CROSS_DIRECTORY_HARDLINKS and NO_INSTALL_HARDLINKS with
INSTALL_SYMLINKS. The result is slightly improved; all symlinks will
point directly to the target rather than via multiple levels of
symlinks.
The rationale was covered in slightly more detail in d56cfc6 ("Use
symlinks instead of hardlinks for installed binaries", 2018-03-15).
Adjust the dangling-relative-symlink filter in the rpmlint config for
the new target of the git-difftool symlink.
Also drop DESTDIR and INSTALL from config.mak; they are both handled via
%make_install.
Remove the rpmlint filter for %buildroot usage which was only needed due
to DESTDIR's use in config.mak.
