checkpatch: try to avoid poor patch subject lines

checkpatch: try to avoid poor patch subject lines

Naming the tool that found an issue in the subject line isn't very useful.
 Emit a warning when a common tool (currently checkpatch, sparse or
smatch) is in the subject line.

Signed-off-by: Joe Perches <[email protected]>
Suggested-by: Al Viro <[email protected]>
Acked-by: Dan Carpenter <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>