checkpatch: Don't warn on pointer to pointer.

Current regexp used to check whitespaces around operators does not
consider that there can be more than one "*" together to express pointer
to pointer.

As a result, false positive warnings are raised when the
patch contains a simple list of pointers, e.g: "char **errrp").

Fix the regexp to allow more than one consecutive "*" characters.

Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Simon Horman <horms@ovn.org>

utilities/checkpatch.py

@@ -739,7 +739,7 @@ infix_operators = \
             '&=', '^=', '|=', '<<=', '>>=']] \
     + [r'[^<" ]<[^=" ]',
        r'[^\->" ]>[^=" ]',
-       r'[^ !()/"]\*[^/]',
+       r'[^ !()/"\*]\*+[^/]',
        r'[^ !&()"]&',
        r'[^" +(]\+[^"+;]',
        r'[^" \-(]\-[^"\->;]',