Fix VMI relocation processing logic error

Fix logic error in VMI relocation processing.  NOPs would always cause
a BUG_ON to fire because the != RELOCATION_NONE in the first if clause
precluding the == VMI_RELOCATION_NOP in the second clause.  Make these
direct equality tests and just warn for unsupported relocation types
(which should never happen), falling back to native in that case.

Thanks to Anthony Liguori for noting this!

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>