HV:vtd.h fixed inline function violations

Inline function have some violations with parentheses
and return type casting.Fixed it.

V1->V2:modified the parameter to ther letter case
V2->V3:move the delcaration to the inner and reduce suffix UL to U

Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: Shawnshh