load tend: Avoid "may be used uninitialized" warnings

load tend: Avoid "may be used uninitialized" warnings

c_load() initializes @ich only when @type is EF_SECTOR.  It also uses
it only then.  Clang is cool with this, but GCC gets confused and
warns "‘ich’ may be used uninitialized".  Ron Koenderink reports
Visual Studio 2019 even flags it as an error.  Same for c_lload() and
c_tend().

Time to clean this up.  Rearrange the code to avoid the warning and
also improve readability a bit.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>