x86: apic.c: xapic_icr_read and x2apic_icr_read should be static

Impact: cleanup, reduce kernel size a bit, avoid sparse warning

Fixes sparse warning:
arch/x86/kernel/apic.c:270:5: warning: symbol 'x2apic_icr_read' was not declared. Should it be static?
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/include/asm/apic.h

@@ -54,7 +54,6 @@ extern int disable_apic;
 extern int is_vsmp_box(void);
 extern void xapic_wait_icr_idle(void);
 extern u32 safe_xapic_wait_icr_idle(void);
-extern u64 xapic_icr_read(void);
 extern void xapic_icr_write(u32, u32);
 extern int setup_profiling_timer(unsigned int);
 

arch/x86/kernel/apic.c

@@ -228,7 +228,7 @@ void xapic_icr_write(u32 low, u32 id)
 	apic_write(APIC_ICR, low);
 }
 
-u64 xapic_icr_read(void)
+static u64 xapic_icr_read(void)
 {
 	u32 icr1, icr2;
 
@@ -268,7 +268,7 @@ void x2apic_icr_write(u32 low, u32 id)
 	wrmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), ((__u64) id) << 32 | low);
 }
 
-u64 x2apic_icr_read(void)
+static u64 x2apic_icr_read(void)
 {
 	unsigned long val;