general code cleanup on lbmk shell scripts

in update/blobs/download, i saw instances where
appdir was being deleted with rm -r, but the more
appropriate command would rm -Rf. this is now fixed.

other than that, i've mostly just simplified a bunch
of if statements and consolidated some duplicated
logic (e.g. if/else block for dependencies in
build_dependencies() of update/blobs/download

one or two functions and/or variables have been
renamed, for greater clarity in the code, also
removed a few messages that were redundant

used printf instead of echo, in a few places, also
fixed up the indentation in a few places

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

resources/scripts/build/clean/crossgcc

@@ -25,14 +25,11 @@ set -u -e
 main()
 {
 	printf "Cleaning crossgcc builds in all coreboot archives\n"
-
 	[ ! -d "coreboot/" ] && exit 0
 
 	for board in coreboot/*; do
-		[ "${board##*/}" = "coreboot" ] && \
-			continue
-		[ ! -d "${board}" ] && \
-			continue
+		[ "${board##*/}" = "coreboot" ] && continue
+		[ ! -d "${board}" ] && continue
 		make -C "${board}/" crossgcc-clean || err "make-clean"
 	done
 }