net, lib/once: remove {net_}get_random_once_wait macro

DO_ONCE(func, ...) will call func with spinlock which acquired by
spin_lock_irqsave in __do_once_start.  But the get_random_once_wait will
sleep in get_random_bytes_wait -> wait_for_random_bytes.

Fortunately, there is no place to use {net_}get_random_once_wait, so we
could remove them simply.

Link: https://lkml.kernel.org/r/20220619074641.40916-1-wuchi.zero@gmail.com
Signed-off-by: wuchi <wuchi.zero@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/net.h

@@ -303,8 +303,6 @@ do {									\
 
 #define net_get_random_once(buf, nbytes)			\
 	get_random_once((buf), (nbytes))
-#define net_get_random_once_wait(buf, nbytes)			\
-	get_random_once_wait((buf), (nbytes))
 
 /*
  * E.g. XFS meta- & log-data is in slab pages, or bcache meta

include/linux/once.h

@@ -54,7 +54,5 @@ void __do_once_done(bool *done, struct static_key_true *once_key,
 
 #define get_random_once(buf, nbytes)					     \
 	DO_ONCE(get_random_bytes, (buf), (nbytes))
-#define get_random_once_wait(buf, nbytes)                                    \
-	DO_ONCE(get_random_bytes_wait, (buf), (nbytes))                      \
 
 #endif /* _LINUX_ONCE_H */