branch, commit, name-rev: ease up boolean conditions

Now that the variables are set by OPT_BOOL, which makes sure
to have the values being 0 or 1 after parsing, we do not need
the double negation to map any other value to 1 for integer
variables.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/commit.c b/builtin/commit.c
index c20426b..b0f86c8 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1072,7 +1072,7 @@
 	if (patch_interactive)
 		interactive = 1;
 
-	if (!!also + !!only + !!all + !!interactive > 1)
+	if (also + only + all + interactive > 1)
 		die(_("Only one of --include/--only/--all/--interactive/--patch can be used."));
 	if (argc == 0 && (also || (only && !amend)))
 		die(_("No paths with --include/--only does not make sense."));