MdeModulePkg/UfsPassThru: Fix wrong GLOBAL_REMOVE_IF_UNREFERENCED usage

MdeModulePkg/UfsPassThru: Fix wrong GLOBAL_REMOVE_IF_UNREFERENCED usage

GLOBAL_REMOVE_IF_UNREFERENCED means __declspec(selectany) for MS tool
chain IA32/X64 build.

According to MSDN, "selectany" would tell the compiler that the declared
global data item (variable or object) is a pick-any COMDAT (a packaged
function). At link time, if multiple definitions of a COMDAT are seen,
the linker picks one and discards the rest.

So we have to remove GLOBAL_REMOVE_IF_UNREFERENCED key word from two global
variable's extern definitions of .h file as we have used this keyword in
.c file, otherwise the MS tool chain would pick the definitions in .h file
and treat it as uninitialized data to generate full-0 content for these two
global variables.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18088 6f19259b-4bc3-4df7-8a09-765794883524