[winpr] fix return values

winpr/libwinpr/utils/image.c

@@ -245,7 +245,7 @@ BYTE* winpr_bitmap_construct_header(size_t width, size_t height, size_t bpp)
 			offset += sizeof(DWORD) * 3; // 3 DWORD color masks
 			break;
 		default:
-			return FALSE;
+			return NULL;
 	}
 
 	if (!writeBitmapFileHeader(s, &bf))

winpr/libwinpr/utils/ini.c

@@ -139,7 +139,7 @@ static FILE* IniFile_Open_File(wIniFile* ini, const char* filename)
 	WINPR_ASSERT(ini);
 
 	if (!filename)
-		return FALSE;
+		return NULL;
 
 	if (ini->readOnly)
 		return winpr_fopen(filename, "rb");