PATCH: remove useless variable tests in runtest.exp

I had overlooked this earlier but noticed it during the review for my 
previous patch that added --local_init and --global_init options.  The 
"convenience abbreviations" "hex" and "decimal" were set only if they do 
not already have a value, but this test is early enough that there is no 
way for them to have been given a value.

----
ChangeLog entry:
----
    	* runtest.exp: Remove useless tests before setting "hex" and
    	"decimal" to regexp fragments.
----

patch:
----
diff --git a/runtest.exp b/runtest.exp
index c7a6f26..b0ddfed 100644
--- a/runtest.exp
+++ b/runtest.exp
@@ -99,12 +99,8 @@ unset -nocomplain env(CCACHE_NODISABLE)
 #
 # some convenience abbreviations
 #
-if {![info exists hex]} {
-    set hex "0x\[0-9A-Fa-f\]+"
-}
-if {![info exists decimal]} {
-    set decimal "\[0-9\]+"
-}
+set hex "0x\[0-9A-Fa-f\]+"
+set decimal "\[0-9\]+"
 
 #
 # set the base dir (current working directory)
----


-- Jacob