Declare EFI_PXE_BASE_CODE correctly

EFI_PXE_BASE_CODE was redefined in the early commit(*) to match the
definition in EDK2. However, EFI_PXE_BASE_CODE wasn't declared
correctly. Since EFI_PXE_BASE_CODE_PROTOCOL is already an alias of
"struct _EFI_PXE_BASE_CODE_PROTOCOL", the additional struct in front of
EFI_PXE_BASE_CODE_PROTOCOL actually confused the compiler and caused
build fail. Remove the redundant struct to avoid confusion.

*751cbce3f640c7 Update global protocol GUIDs definitions to match EDK2

Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Nigel Croxon <ncroxon@redhat.com>

inc/efipxebc.h

@@ -419,7 +419,7 @@ typedef struct _EFI_PXE_BASE_CODE_PROTOCOL {
 // Use 'EFI_PXE_BASE_CODE_PROTOCOL_GUID' instead.
 
 typedef struct _EFI_PXE_BASE_CODE_PROTOCOL _EFI_PXE_BASE_CODE;
-typedef struct EFI_PXE_BASE_CODE_PROTOCOL EFI_PXE_BASE_CODE;
+typedef EFI_PXE_BASE_CODE_PROTOCOL EFI_PXE_BASE_CODE;
 
 //
 // Call Back Definitions