trees: don't check if xgcc is already built

just run the make crossgcc command anyway.
coreboot's own build system checks itself, and much
more reliably, but the check is more thorough and a bit
slower.

in rare cases, lbmk may come into build issues with xgcc,
and if you run the build again, it will always fail every
time because the checks is based on whether the xgcc
directory exists, rather than checking each
individual crossgcc binary.

checking every binary is also possible, but as i said,
the coreboot build system already does that, so let's defer
to coreboot's own handling of it.

remove the directory check. this will slow down the build
process a little bit, but should improve reliability under
fault conditions.

Signed-off-by: Leah Rowe <leah@libreboot.org>

script/trees

@@ -170,7 +170,6 @@ check_cross_compiler()
 		export CROSS_COMPILE="${xarch% *}-"
 		[ -n "$xlang" ] && export BUILD_LANGUAGES="$xlang"
 
-		[ -d "$cbdir/util/crossgcc/xgcc/$_xarch/" ] && continue
 		x_ make -C "$cbdir" crossgcc-${_xarch%-*} $cbmakeargs
 	done
 }