checkpatch: Add acheck for use of sizeof without parenthesis

Kernel style uses parenthesis around sizeof.

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

@@ -3265,6 +3265,12 @@ sub process {
 			     "sizeof(& should be avoided\n" . $herecurr);
 		}
 
+# check for sizeof without parenthesis
+		if ($line =~ /\bsizeof\s+((?:\*\s*|)$Lval|$Type(?:\s+$Lval|))/) {
+			WARN("SIZEOF_PARENTHESIS",
+			     "sizeof $1 should be sizeof($1)\n" . $herecurr);
+		}
+
 # check for line continuations in quoted strings with odd counts of "
 		if ($rawline =~ /\\$/ && $rawline =~ tr/"/"/ % 2) {
 			WARN("LINE_CONTINUATIONS",