Git does not know what the contents in the index should be for a
path added with "git add -N" yet, so "git grep --cached" should not
show hits (or show lack of hits, with -L) in such a path, but that
logic does not apply to "git grep", i.e. searching in the working
tree files. But we did so by mistake, which has been corrected.
* nd/ita-cleanup:
grep: fix grepping for "intent to add" files
t7810-grep.sh: fix a whitespace inconsistency
t7810-grep.sh: fix duplicated test name