updated read me windows file path

Author: vic-tsang

cpp/src/arrow/flight/sql/odbc/README

@@ -11,9 +11,9 @@ After the build succeeds, the ODBC DLL will be located in
     i. `cd to repo.`
     ii. `cd <path\to\repo>`
     iii. Run script to register your ODBC DLL as Apache Arrow Flight SQL ODBC Driver
-    `.\cpp\src\arrow\flight\sql\odbc\install\install_amd64.cmd <path\to\repo>\cpp\build\< release | debug >\< Release | Debug>\arrow_flight_sql_odbc.dll`
+    `.\cpp\src\arrow\flight\sql\odbc\install\windows\install_amd64.cmd <path\to\repo>\cpp\build\< release | debug >\< Release | Debug>\arrow_flight_sql_odbc.dll`
     Example command for reference:
-    `.\cpp\src\arrow\flight\sql\odbc\install\install_amd64.cmd C:\path\to\arrow\cpp\build\release\Release\arrow_flight_sql_odbc.dll`
+    `.\cpp\src\arrow\flight\sql\odbc\install\windows\install_amd64.cmd C:\path\to\arrow\cpp\build\release\Release\arrow_flight_sql_odbc.dll`
 
 If the registration is successful, then Apache Arrow Flight SQL ODBC Driver 
 should show as an available ODBC driver in the x64 ODBC Driver Manager.