bash completion: factor submodules into dirty state

In the implementation of GIT_PS1_SHOWDIRTYSTATE in 738a94a9 (bash:
offer to show (un)staged changes, 2009-02-03), I cut&pasted the
git-diff invocations from dirty-worktree checks elsewhere, carrying
along the --ignore-submodules option.

As pointed out by Kevin Ballard, this doesn't really make sense: to
the _user_, a changed submodule counts towards uncommitted changes.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -148,11 +148,9 @@ __git_ps1 ()
 		elif [ "true" = "$(git rev-parse --is-inside-work-tree 2>/dev/null)" ]; then
 			if [ -n "${GIT_PS1_SHOWDIRTYSTATE-}" ]; then
 				if [ "$(git config --bool bash.showDirtyState)" != "false" ]; then
-					git diff --no-ext-diff --ignore-submodules \
-						--quiet --exit-code || w="*"
+					git diff --no-ext-diff --quiet --exit-code || w="*"
 					if git rev-parse --quiet --verify HEAD >/dev/null; then
-						git diff-index --cached --quiet \
-							--ignore-submodules HEAD -- || i="+"
+						git diff-index --cached --quiet HEAD -- || i="+"
 					else
 						i="#"
 					fi