rcu-tasks: Always inline rcu_irq_work_resched()

Thanks to CONFIG_DEBUG_SECTION_MISMATCH, empty functions can be
generated out of line.  rcu_irq_work_resched() can be called from
noinstr code, so make sure it's always inlined.

Fixes: 5645064 ("rcu/context-tracking: Move deferred nocb resched to context tracking")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/e84f15f013c07e4c410d972e75620c53b62c1b3e.1743481539.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/d1eca076-fdde-484a-b33e-70e0d167c36d@infradead.org

Author: jpoimboe

include/linux/rcupdate.h

@@ -132,7 +132,7 @@ static inline void rcu_sysrq_end(void) { }
 #if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_KVM_XFER_TO_GUEST_WORK))
 void rcu_irq_work_resched(void);
 #else
-static inline void rcu_irq_work_resched(void) { }
+static __always_inline void rcu_irq_work_resched(void) { }
 #endif
 
 #ifdef CONFIG_RCU_NOCB_CPU