SDL_rtf: cmake: use SONAME instead of full name for shared vendored libraries

SDL Commits
1 
From 09330321921948f185b4e3bd8c9d2d9dcfe6179e Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Tue, 5 Sep 2023 23:41:17 +0200
Subject: [PATCH] cmake: use SONAME instead of full name for shared vendored
 libraries

---
 cmake/PrivateSdlFunctions.cmake | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/cmake/PrivateSdlFunctions.cmake b/cmake/PrivateSdlFunctions.cmake
index ebc0c1e..96493bd 100644
--- a/cmake/PrivateSdlFunctions.cmake
+++ b/cmake/PrivateSdlFunctions.cmake
@@ -196,7 +196,12 @@ function(target_get_dynamic_library DEST TARGET)
         endif()
         set (result "$<TARGET_FILE_NAME:${TARGET}>")
     endif()
-    set(${DEST} ${result} PARENT_SCOPE)
+    # TARGET_SONAME_FILE is not allowed for DLL target platforms.
+    if(WIN32)
+        set(result "$<TARGET_FILE_NAME:${TARGET}>")
+    else()
+        set(result "$<TARGET_SONAME_FILE_NAME:${TARGET}>")
+    endif()
 endfunction()
 
 macro(sdl_check_project_in_subfolder relative_subfolder name vendored_option)