ShellPkg-UefiShellCommandLib: Add EFIAPI in VA_List library function

Add EFIAPI in CatPrint library function. Every function which uses
variable list need explicit use EFIAPI to force use MS ABI. This change
is needed to pass CLANG38 build.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Steven Shi <steven.shi@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>

ShellPkg/Library/UefiShellCommandLib/ConsistMapping.c

@@ -85,6 +85,7 @@ typedef struct {
 
 **/
 EFI_STATUS
+EFIAPI
 CatPrint (
   IN OUT POOL_PRINT   *Str,
   IN CHAR16           *Fmt,