t0302 & t3900: add forgotten quotes

When cleaning up files in the $HOME directory, it really makes sense to
quote the path, especially in Git's test suite, where the HOME directory
is *guaranteed* to contain spaces in its name.

It would appear that those two tests pass even without cleaning up the
files, but really more by pure chance than by design (the cleanup seems
not actually to be necessary).

However, if anybody would have a left-over `trash/` directory in Git's
`t/` directory, these tests would fail, because they would all of a
sudden try to delete that directory, but without the `-r` (recursive)
flag. That is how this issue was found.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0302-credential-store.sh

@@ -37,7 +37,7 @@ helper_test store
 unset XDG_CONFIG_HOME
 
 test_expect_success 'if custom xdg file exists, home and xdg files not created' '
-	test_when_finished "rm -f $HOME/xdg/git/credentials" &&
+	test_when_finished "rm -f \"$HOME/xdg/git/credentials\"" &&
 	test -s "$HOME/xdg/git/credentials" &&
 	test_path_is_missing "$HOME/.git-credentials" &&
 	test_path_is_missing "$HOME/.config/git/credentials"

t/t3900-i18n-commit.sh

@@ -40,7 +40,7 @@ test_expect_success 'UTF-16 refused because of NULs' '
 '
 
 test_expect_success 'UTF-8 invalid characters refused' '
-	test_when_finished "rm -f $HOME/stderr $HOME/invalid" &&
+	test_when_finished "rm -f \"$HOME/stderr $HOME/invalid\"" &&
 	echo "UTF-8 characters" >F &&
 	printf "Commit message\n\nInvalid surrogate:\355\240\200\n" \
 		>"$HOME/invalid" &&
@@ -49,7 +49,7 @@ test_expect_success 'UTF-8 invalid characters refused' '
 '
 
 test_expect_success 'UTF-8 overlong sequences rejected' '
-	test_when_finished "rm -f $HOME/stderr $HOME/invalid" &&
+	test_when_finished "rm -f \"$HOME/stderr $HOME/invalid\"" &&
 	rm -f "$HOME/stderr" "$HOME/invalid" &&
 	echo "UTF-8 overlong" >F &&
 	printf "\340\202\251ommit message\n\nThis is not a space:\300\240\n" \
@@ -59,7 +59,7 @@ test_expect_success 'UTF-8 overlong sequences rejected' '
 '
 
 test_expect_success 'UTF-8 non-characters refused' '
-	test_when_finished "rm -f $HOME/stderr $HOME/invalid" &&
+	test_when_finished "rm -f \"$HOME/stderr $HOME/invalid\"" &&
 	echo "UTF-8 non-character 1" >F &&
 	printf "Commit message\n\nNon-character:\364\217\277\276\n" \
 		>"$HOME/invalid" &&
@@ -68,7 +68,7 @@ test_expect_success 'UTF-8 non-characters refused' '
 '
 
 test_expect_success 'UTF-8 non-characters refused' '
-	test_when_finished "rm -f $HOME/stderr $HOME/invalid" &&
+	test_when_finished "rm -f \"$HOME/stderr $HOME/invalid\"" &&
 	echo "UTF-8 non-character 2." >F &&
 	printf "Commit message\n\nNon-character:\357\267\220\n" \
 		>"$HOME/invalid" &&