xbmk: general cleanup

note: mecleaner check removed in vendor.sh, because
it's already guaranteed to be fetched. the check will
never indicate failure, so we can just assume that
the me cleaner python script exists.

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

include/env/get.sh

@@ -39,14 +39,12 @@ single_tree_fetch()
 			x_ "$mk" -f $d
 		done
 
-	clone_project
+	$if_single_tree \
+		clone_project; :
 }
 
 clone_project()
 {
-	singletree "$project" || \
-		return 0
-
 	loc="src/$project"
 	[ -d "$loc" ] && \
 		return 0
@@ -174,10 +172,8 @@ try_fetch_curl()
 		try_$2 "$cached" "$@" || \
 			return 1
 
-	[ -f "$5" ] && \
-		if bad_checksum "$6" "$5" 2>/dev/null; then
-			x_ cp "$cached" "$5"
-		fi
+	[ -f "$5" ] && bad_checksum "$6" "$5" 2>/dev/null && \
+		x_ cp "$cached" "$5"
 
 	if [ ! -f "$cached" ]; then
 		return 1
@@ -202,8 +198,7 @@ try_curl()
 	ua="Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0"
 
 	( x_ curl --location --retry 3 -A "$ua" "$2" -o "$1" ) \
-	    || ( x_ wget --tries 3 -U "$ua" "$2" -O "$1" ) \
-	    || return 1; :
+	    || ( x_ wget --tries 3 -U "$ua" "$2" -O "$1" ) || return 1; :
 }
 
 try_copy()
@@ -230,15 +225,9 @@ try_git()
 		x_ mv "$tmpgitcache" "$gitdest"
 	fi
 
-	if git -C "$gitdest" show "$7" 1>/dev/null 2>/dev/null && \
-	    [ "$forcepull" != "y" ]; then
-		# don't try to pull the latest changes if the given target
-		# revision already exists locally. this saves a lot of time
-		# during release builds, and reduces the chance that we will
-		# interact with grub.git or gnulib.git overall during runtime
-
-		return 0
-	fi
+	git -C "$gitdest" show "$7" 1>/dev/null 2>/dev/null && \
+	    [ "$forcepull" != "y" ] && \
+		return 0 # don't pull changes if target rev exists locally
 
 	if [ "$XBMK_CACHE_MIRROR" = "y" ]; then
 		( x_ git -C "$gitdest" fetch ) || :; :
@@ -250,9 +239,8 @@ try_git()
 
 bad_checksum()
 {
-	if e "$2" f missing; then
+	e "$2" f missing && \
 		return 0
-	fi
 
 	build_sbase
 	csum="$(x_ "$sha512sum" "$2" | awk '{print $1}')" || \