u64_stat: Remove the obsolete fetch_irq() variants.

There are no more users of the obsolete interface
u64_stats_fetch_begin_irq() and u64_stats_fetch_retry_irq().

Remove the obsolete API.

[bigeasy: Split out the bits from a larger patch].
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20230110160738.974085-1-bigeasy@linutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/u64_stats_sync.h

@@ -213,16 +213,4 @@ static inline bool u64_stats_fetch_retry(const struct u64_stats_sync *syncp,
 	return __u64_stats_fetch_retry(syncp, start);
 }
 
-/* Obsolete interfaces */
-static inline unsigned int u64_stats_fetch_begin_irq(const struct u64_stats_sync *syncp)
-{
-	return u64_stats_fetch_begin(syncp);
-}
-
-static inline bool u64_stats_fetch_retry_irq(const struct u64_stats_sync *syncp,
-					     unsigned int start)
-{
-	return u64_stats_fetch_retry(syncp, start);
-}
-
 #endif /* _LINUX_U64_STATS_SYNC_H */