tests: make the code more readable

Replace the parsing of the output of "ls -l" by test_path_is_symlink() and
test_readlink().

Signed-off-by: COGONI Guillaume <cogoni.guillaume@gmail.com>
Co-authored-by: BRESSAT Jonathan <git.jonathan.bressat@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3903-stash.sh

@@ -393,7 +393,8 @@ test_expect_success SYMLINKS 'stash file to symlink' '
 	test_path_is_file_not_symlink file &&
 	test bar = "$(cat file)" &&
 	git stash apply &&
-	case "$(ls -l file)" in *" file -> file2") :;; *) false;; esac
+	test_path_is_symlink file &&
+	test "$(test_readlink file)" = file2
 '
 
 test_expect_success SYMLINKS 'stash file to symlink (stage rm)' '
@@ -404,7 +405,8 @@ test_expect_success SYMLINKS 'stash file to symlink (stage rm)' '
 	test_path_is_file_not_symlink file &&
 	test bar = "$(cat file)" &&
 	git stash apply &&
-	case "$(ls -l file)" in *" file -> file2") :;; *) false;; esac
+	test_path_is_symlink file &&
+	test "$(test_readlink file)" = file2
 '
 
 test_expect_success SYMLINKS 'stash file to symlink (full stage)' '
@@ -416,7 +418,8 @@ test_expect_success SYMLINKS 'stash file to symlink (full stage)' '
 	test_path_is_file_not_symlink file &&
 	test bar = "$(cat file)" &&
 	git stash apply &&
-	case "$(ls -l file)" in *" file -> file2") :;; *) false;; esac
+	test_path_is_symlink file &&
+	test "$(test_readlink file)" = file2
 '
 
 # This test creates a commit with a symlink used for the following tests