tests: avoid checking the exitcode of false

Solaris false returns 255 instead of 1, so we remove one unneeded instance and
replaces another with (exit 1) as suggested by Brodie Rao.

tests/test-bisect.t

@@ -269,9 +269,6 b' skip'
   date:        Thu Jan 01 00:00:01 1970 +0000
   summary:     msg 1
   
-  $ false
-  [1]
-
 
   $ hg bisect -r
   $ hg bisect -g tip

tests/test-run-tests.t

@@ -33,5 +33,5 b' Literal match ending in " (re)":'
 
 Exit code:
 
-  $ false
+  $ (exit 1) 
   [1]