x86/apic/uv: Make x2apic_extra_bits static

Not used outside of the UV apic source.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105219.725264153@linutronix.de

arch/x86/include/asm/apic.h

@@ -467,8 +467,6 @@ static inline unsigned default_get_apic_id(unsigned long x)
 
 #ifdef CONFIG_X86_64
 extern void apic_send_IPI_self(int vector);
-
-DECLARE_PER_CPU(int, x2apic_extra_bits);
 #endif
 
 extern void generic_bigsmp_probe(void);

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -22,7 +22,7 @@
 #include <asm/uv/uv.h>
 #include <asm/apic.h>
 
-DEFINE_PER_CPU(int, x2apic_extra_bits);
+static DEFINE_PER_CPU(int, x2apic_extra_bits);
 
 static enum uv_system_type	uv_system_type;
 static bool			uv_hubless_system;