x86/speculation: Remove redundant arch_smt_update() invocation

x86/speculation: Remove redundant arch_smt_update() invocation

With commit a74cfffb03b7 ("x86/speculation: Rework SMT state change"),
arch_smt_update() is invoked from each individual CPU hotplug function.

Therefore the extra arch_smt_update() call in the sysfs SMT control is
redundant.

Fixes: a74cfffb03b7 ("x86/speculation: Rework SMT state change")
Signed-off-by: Zhenzhong Duan <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Link: https://lkml.kernel.org/r/e2e064f2-e8ef-42ca-bf4f-76b612964752@default