t1007: modernize malformed object tests

The tests in t1007 for detecting malformed objects have two
anachronisms:

 - they use "sha1" instead of "oid" in variable names, even though the
   script as a whole has been adapted to handle sha256

 - they use test_i18ngrep, which is no longer necessary

Since we'll be adding a new similar test, let's clean these up so they
are all consistently using the modern style.

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

t/t1007-hash-object.sh

@@ -203,23 +203,23 @@ done
 test_expect_success 'too-short tree' '
 	echo abc >malformed-tree &&
 	test_must_fail git hash-object -t tree malformed-tree 2>err &&
-	test_i18ngrep "too-short tree object" err
+	grep "too-short tree object" err
 '
 
 test_expect_success 'malformed mode in tree' '
-	hex_sha1=$(echo foo | git hash-object --stdin -w) &&
-	bin_sha1=$(echo $hex_sha1 | hex2oct) &&
-	printf "9100644 \0$bin_sha1" >tree-with-malformed-mode &&
+	hex_oid=$(echo foo | git hash-object --stdin -w) &&
+	bin_oid=$(echo $hex_oid | hex2oct) &&
+	printf "9100644 \0$bin_oid" >tree-with-malformed-mode &&
 	test_must_fail git hash-object -t tree tree-with-malformed-mode 2>err &&
-	test_i18ngrep "malformed mode in tree entry" err
+	grep "malformed mode in tree entry" err
 '
 
 test_expect_success 'empty filename in tree' '
-	hex_sha1=$(echo foo | git hash-object --stdin -w) &&
-	bin_sha1=$(echo $hex_sha1 | hex2oct) &&
-	printf "100644 \0$bin_sha1" >tree-with-empty-filename &&
+	hex_oid=$(echo foo | git hash-object --stdin -w) &&
+	bin_oid=$(echo $hex_oid | hex2oct) &&
+	printf "100644 \0$bin_oid" >tree-with-empty-filename &&
 	test_must_fail git hash-object -t tree tree-with-empty-filename 2>err &&
-	test_i18ngrep "empty filename in tree entry" err
+	grep "empty filename in tree entry" err
 '
 
 test_expect_success 'corrupt commit' '