drivers/net/wireless/ipw2x00/ipw2100.c: introduce missing initialization

The result of one call to a function is tested, and then at the second call
to the same function, the previous result, and not the current result, is
tested again.

Also changed &bssid to bssid, at the suggestion of Stanislav Yakovlev.

The semantic match that finds the first problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression ret;
identifier f;
statement S1,S2;
@@

*ret = f(...);
if (\(ret != 0\|ret < 0\|ret == NULL\)) S1
... when any
*f(...);
if (\(ret != 0\|ret < 0\|ret == NULL\)) S2
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: John W. Linville <linville@tuxdriver.com>