rtl8187: fix retry count passed in rtl8187_tx

I mistakenly changed retry count passed in rtl8187_tx in previous change
"rtl8187: feedback transmitted packets using tx close descriptor for
8187B". For 8187 it should represent the number of retries (retry count
limit). As explained by Johannes Berg, .count represents the number of
tries (not retries), and retries = tries - 1.

Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Tested-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>