ShellPkg/UefiHandleParsingLib: Fix error allocate pool

ShellPkg/UefiHandleParsingLib: Fix error allocate pool

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1965

For function InsertNewGuidNameMapping, it rellocate the
mGuidList with new size
"mGuidListCount+1 * sizeof(GUID_INFO_BLOCK)". That isn't
its purpose and would cause a overflow operation in
"mGuidList[mGuidListCount - 1].xxx = xxx". Its purpose
is to increase 1 block size of mGuidList. Change it to
"(mGuidListCount + 1) * sizeof (GUID_INFO_BLOCK)".

Adjust the coding style of this function.

Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Andrew Fish <afish@apple.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>