test: use a fully spec locale name in RunGrepTest

A locale contains an optional charmap that might be relevant in
determining if the setlocale() function considers it valid.

Change the bad locale used when testing to one that contains also
an invalid charmap and therefore fix this test in OpenBSD.

RunGrepTest

@@ -842,11 +842,11 @@ echo "RC=$?" >>testtrygrep
 echo "---------------------------- Test 150 -----------------------------" >>testtrygrep
 which locale >/dev/null 2>&1
 if [ $? -ne 0 ]; then
-  echo "pcre2grep: Failed to set locale badlocale (obtained from LC_CTYPE)" >>testtrygrep
+  echo "pcre2grep: Failed to set locale locale.bad (obtained from LC_CTYPE)" >>testtrygrep
   echo "RC=2" >>testtrygrep
 else
 
-  (cd $srcdir; unset LC_ALL; env LC_CTYPE=badlocale $valgrind $vjs $pcre2grep abc /dev/null) >>testtrygrep 2>&1
+  (cd $srcdir; unset LC_ALL; env LC_CTYPE=locale.bad $valgrind $vjs $pcre2grep abc /dev/null) >>testtrygrep 2>&1
   echo "RC=$?" >>testtrygrep
 fi
 

testdata/grepoutput

@@ -1225,7 +1225,7 @@ Usage: pcre2grep [-AaBCcDdEeFfHhIilLMmNnOoPqrstuUVvwxZ] [long options] [pattern]
 Type "pcre2grep --help" for more information and the long options.
 RC=2
 ---------------------------- Test 150 -----------------------------
-pcre2grep: Failed to set locale badlocale (obtained from LC_CTYPE)
+pcre2grep: Failed to set locale locale.bad (obtained from LC_CTYPE)
 RC=2
 ---------------------------- Test 151 -----------------------------
 The quick brown