test: use test_expect_equal_file in atomicity

The documentation claims this is more robust, and it seems to work
fine to switch to the _file variant.

diff --git a/test/atomicity b/test/atomicity
index ca5c44d7ec7af1a136c67f0623c50442f2036543..88b39587b355878858ec95e11b3277bbee8680c9 100755 (executable)
--- a/test/atomicity
+++ b/test/atomicity
@@ -95,7 +95,7 @@ done
 
 test_begin_subtest '"notmuch new" is idempotent under arbitrary aborts'
 test_subtest_known_broken
-test_expect_equal GDB "$(cat searchall)" "$(cat expectall)"
+test_expect_equal_file GDB searchall expectall
 
 test_expect_success GDB "detected $outcount>10 abort points" "test $outcount -gt 10"