Apply suggestions from code review

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: ScottMunroMS

Include/httpClient/pal.h

@@ -89,7 +89,7 @@ typedef int32_t HRESULT;
 #define __cdecl
 #endif
 
-#ifndef __stdcal
+#ifndef __stdcall
 #define __stdcall
 #endif
 
@@ -133,7 +133,9 @@ typedef void* HANDLE;
 #define FACILITY_INTERNET                12
 #define FACILITY_HTTP                    25
 
+#ifndef _HRESULT_TYPEDEF_
 #define _HRESULT_TYPEDEF_(_sc) ((HRESULT)_sc)
+#endif
 #define __HRESULT_FROM_WIN32(x) ((HRESULT)(x) <= 0 ? ((HRESULT)(x)) : ((HRESULT) (((x) & 0x0000FFFF) | (FACILITY_WIN32 << 16) | 0x80000000)))
 
 #define S_OK                                    _HRESULT_TYPEDEF_(0x00000000L)