x86/apic: Fix a warning message in logical CPU IDs allocation

The current warning message in allocate_logical_cpuid() is somewhat confusing:

  Only 1 processors supported.Processor 2/0x2 and the rest are ignored.

As it might imply that there's only one CPU in the system - while what we ran
into here is a kernel limitation.

Fix the warning message to clarify all that:

  APIC: NR_CPUS/possible_cpus limit of 2 reached. Processor 2/0x2 and the rest are ignored.

( Also update the error return from -1 to -EINVAL, which is the more
  canonical return value. )

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@alien8.de
Cc: nicstange@gmail.com
Cc: wanpeng.li@hotmail.com
Link: http://lkml.kernel.org/r/1488261052-25753-1-git-send-email-douly.fnst@cn.fujitsu.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>