checkpatch: change CamelCase test and make it --strict

Do not bleat a message on nominally acceptable CamelCase uses that are
separated by an _ like drm_core_has_MTRR.

CamelCase tests are also a bit noisy against certain types of code
acceptable to some kernel developers.

Make the test applicable only with --strict.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -2938,12 +2938,12 @@ sub process {
 		while ($line =~ m{($Constant|$Lval)}g) {
 			my $var = $1;
 			if ($var !~ /$Constant/ &&
-			    $var =~ /[A-Z]\w*[a-z]|[a-z]\w*[A-Z]/ &&
+			    $var =~ /[A-Z][a-z]|[a-z][A-Z]/ &&
 			    $var !~ /"^(?:Clear|Set|TestClear|TestSet|)Page[A-Z]/ &&
 			    !defined $camelcase{$var}) {
 				$camelcase{$var} = 1;
-				WARN("CAMELCASE",
-				     "Avoid CamelCase: <$var>\n" . $herecurr);
+				CHK("CAMELCASE",
+				    "Avoid CamelCase: <$var>\n" . $herecurr);
 			}
 		}