checkpatch: improve network block comment style checking

checkpatch: improve network block comment style checking

Some comment styles in net and drivers/net are flagged inappropriately.

Avoid proclaiming inline comments like:
	int a = b;	/* some comment */
and block comments like:
	/*********************
	 * some comment
	 ********************/
are defective.

Tested with
$ cat drivers/net/t.c
/* foo */

/*
 * foo
 */

/* foo
 */

/* foo
 * bar */

/****************************
 * some long block comment
 ***************************/

struct foo {
	int bar;	/* another test */
};
$

Signed-off-by: Joe Perches <[email protected]>
Reported-by: Larry Finger <[email protected]>
Cc: David Miller <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>