[PATCH] gitk: fix 'can't read "notflag"'

Sometimes, when calling git bisect visualize, parameters including
a "--not" are passed to gitk, triggering an uninitialized-variable bug
introduced in ee66e089(gitk: Make updates go faster).

Noticed by Alejandro Riveira Fernández.

Signed-off-by: Johannes Schindelin <johannes.schindelin <at> gmx.de>
---

	On Wed, 3 Dec 2008, Alejandro Riveira wrote:

	> $ git bisect visualize                                                                  (03-12 12:16)
	> Error in startup script: can't read "notflag": no such variable

	Alejandro was good enough to test this fix.

 gitk-git/gitk |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/gitk-git/gitk b/gitk-git/gitk
index 3353f4a..b18bdf0 100644
--- a/gitk-git/gitk
+++ b/gitk-git/gitk
@@ -139,6 +139,7 @@ proc parseviewargs {n arglist} {
     set origargs $arglist
     set allknown 1
     set filtered 0
+    set notflag 0
     set i -1