tests: handle paths with whitespace

v2: incorporate remarks of Lukas

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>

tests/setup.sh

@@ -41,7 +41,7 @@ mkrepo() {
 		git commit -m "add a+b"
 		git branch "1+2"
 	fi
-	cd $dir
+	cd "$dir"
 }
 
 setup_repos()

tests/t0108-patch.sh

@@ -25,7 +25,7 @@ run_test 'find `cgit` signature' '
 '
 
 run_test 'find initial commit' '
-	root=$(git --git-dir=$PWD/trash/repos/foo/.git rev-list HEAD | tail -1)
+	root=$(git --git-dir="$PWD/trash/repos/foo/.git" rev-list HEAD | tail -1)
 '
 
 run_test 'generate patch for initial commit' '