arch:x86:xen: Remove unnecessary assignment in xen_apic_read()

In the function xen_apic_read(), the initialized value of 'ret' is unused
because it will be assigned by the function HYPERVISOR_platform_op(),
thus remove it.

Signed-off-by: jianchunfu <jianchunfu@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20220314070514.2602-1-jianchunfu@cmss.chinamobile.com
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

arch/x86/xen/apic.c

@@ -51,7 +51,7 @@ static u32 xen_apic_read(u32 reg)
 		.interface_version = XENPF_INTERFACE_VERSION,
 		.u.pcpu_info.xen_cpuid = 0,
 	};
-	int ret = 0;
+	int ret;
 
 	/* Shouldn't need this as APIC is turned off for PV, and we only
 	 * get called on the bootup processor. But just in case. */