Fix "can not" in Documentation and Kconfig

Randy brought it to my attention that in proper english "can not" should always
be written "cannot". I donot see any reason to argue, even if I mightnot
understand why this rule exists.  This patch fixes "can not" in several
Documentation files as well as three Kconfigs.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

Documentation/stable_kernel_rules.txt

@@ -4,7 +4,7 @@ Rules on what kind of patches are accepted, and which ones are not, into the
 "-stable" tree:
 
  - It must be obviously correct and tested.
- - It can not be bigger than 100 lines, with context.
+ - It cannot be bigger than 100 lines, with context.
  - It must fix only one thing.
  - It must fix a real bug that bothers people (not a, "This could be a
    problem..." type thing).
@@ -14,7 +14,7 @@ Rules on what kind of patches are accepted, and which ones are not, into the
    critical.
  - No "theoretical race condition" issues, unless an explanation of how the
    race can be exploited is also provided.
- - It can not contain any "trivial" fixes in it (spelling changes,
+ - It cannot contain any "trivial" fixes in it (spelling changes,
    whitespace cleanups, etc).
  - It must be accepted by the relevant subsystem maintainer.
  - It must follow the Documentation/SubmittingPatches rules.