checksrc: fix typo in comment

enfore -> enforce

Closes #8281

lib/checksrc.pl

@@ -827,7 +827,7 @@ sub scanfile {
         # A rather more interesting, and correct, check would be to not test
         # only locally committed files but inspect all files wrt the year of
         # their last commit. Removing the `git rev-list origin/master..HEAD`
-        # condition below will enfore copyright year checks against the year
+        # condition below will enforce copyright year checks against the year
         # the file was last committed (and thus edited to some degree).
         my $commityear = undef;
         @copyright = sort {$$b{year} cmp $$a{year}} @copyright;