Fix typo in Darwin CMake script

Author: withSang

Xcode/SDL/pkg-support/resources/CMake/SDL3Config.cmake

@@ -38,7 +38,6 @@ set(_current_path "${CMAKE_CURRENT_LIST_DIR}")
 get_filename_component(_current_path "${_current_path}" REALPATH)
 set(_sdl3_framework_path "")
 
-set(_current_path "${_sdl3_framework_path}")
 while(NOT _sdl3_framework_path)
     if (IS_DIRECTORY "${_current_path}" AND "${_current_path}" MATCHES "/SDL3\\.framework$")
         set(_sdl3_framework_path "${_current_path}")
@@ -48,10 +47,10 @@ while(NOT _sdl3_framework_path)
     if ("${_current_path}" STREQUAL "${_next_current_path}")
         break()
     endif()
-    set(_next_current_path "${_current_path}")
-endforeach()
-set(_next_current_path)
-set(_next_current_path)
+    set(_current_path "${_next_current_path}")
+endwhile()
+unset(_current_path)
+unset(_next_current_path)
 
 if(NOT _sdl3_framework_path)
     message(FATAL_ERROR "Could not find SDL3.framework root from ${CMAKE_CURRENT_LIST_DIR}")