watchdog: ie6xx_wdt: section mismatch in ie6xx_wdt_probe()

ie6xx_wdt_probe() calls ie6xx_wdt_debugfs_exit() as part of
it's error cleanup path, and ie6xx_wdt_debugfs_exit() is
currently annotated __devexit.

Signed-off-by: Gerard Snitselaar <dev@snitselaar.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>