patch 8.2.4081: CodeQL reports problem in if_cscope causing it to fail

Problem:    CodeQL reports problem in if_cscope causing it to fail.
Solution:   Use execvp() instead of execl().  Merge the header file into the
            source file. (Ozaki Kiichi, closes #9519)
diff --git a/src/testdir/test_cscope.vim b/src/testdir/test_cscope.vim
index c01ca32..ba19419 100644
--- a/src/testdir/test_cscope.vim
+++ b/src/testdir/test_cscope.vim
@@ -246,7 +246,7 @@
     " Test: 'csprg' option
     call assert_equal('cscope', &csprg)
     set csprg=doesnotexist
-    call assert_fails('cscope add Xcscope2.out', 'E609:')
+    call assert_fails('cscope add Xcscope2.out', 'E262:')
     set csprg=cscope
 
     " Test: multiple cscope connections