t4010-diff-pathspec.sh: use the $( ... ) construct for command substitution

diff --git a/t/t4010-diff-pathspec.sh b/t/t4010-diff-pathspec.sh
index 2bb973655bf043cc43292764ffd68becda25aa2e..bf078418662c4bab4e512be8fc22a5aa76466119 100755 (executable)
--- a/t/t4010-diff-pathspec.sh
+++ b/t/t4010-diff-pathspec.sh
@@ -18,7 +18,7 @@ test_expect_success \
      mkdir path1 &&
      echo rezrov >path1/file1 &&
      git update-index --add file0 path1/file1 &&
-     tree=`git write-tree` &&
+     tree=$(git write-tree) &&
      echo "$tree" &&
      echo nitfol >file0 &&
      echo yomin >path1/file1 &&
@@ -131,7 +131,7 @@ test_expect_success 'diff multiple wildcard pathspecs' '
        mkdir path2 &&
        echo rezrov >path2/file1 &&
        git update-index --add path2/file1 &&
-       tree3=`git write-tree` &&
+       tree3=$(git write-tree) &&
        git diff --name-only $tree $tree3 -- "path2*1" "path1*1" >actual &&
        cat <<-\EOF >expect &&
        path1/file1