speakup: fix uninitialized flush_lock

BugLink: https://bugs.launchpad.net/bugs/1910822

[ Upstream commit d1b928e ]

The flush_lock is uninitialized, use DEFINE_SPINLOCK
to define and initialize flush_lock.

Fixes: c6e3fd2 ("Staging: add speakup to the staging directory")
Reported-by: Hulk Robot <[email protected]>
Reviewed-by: Samuel Thibault <[email protected]>
Signed-off-by: Yang Yingliang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Kelsey Skunberg <[email protected]>

Author: Yang Yingliang

drivers/staging/speakup/speakup_dectlk.c

@@ -37,7 +37,7 @@ static unsigned char get_index(struct spk_synth *synth);
 static int in_escape;
 static int is_flushing;
 
-static spinlock_t flush_lock;
+static DEFINE_SPINLOCK(flush_lock);
 static DECLARE_WAIT_QUEUE_HEAD(flush);
 
 static struct var_t vars[] = {