git-bisect.sh: avoid "test <cond> -a/-o <cond>"

The construct is error-prone; "test" being built-in in most modern
shells, the reason to avoid "test <cond> && test <cond>" spawning
one extra process by using a single "test <cond> -a <cond>" no
longer exists.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/git-bisect.sh b/git-bisect.sh
index af4d04c..1e0d602 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -408,7 +408,7 @@
 	bisect_reset
 	while read git bisect command rev
 	do
-		test "$git $bisect" = "git bisect" -o "$git" = "git-bisect" || continue
+		test "$git $bisect" = "git bisect" || test "$git" = "git-bisect" || continue
 		if test "$git" = "git-bisect"
 		then
 			rev="$command"