Remove use of p:, fix install error check

Author: FreddieAkeroyd

build/update_genie_python.bat

@@ -1,23 +1,18 @@
-setlocal
+setlocal EnableDelayedExpansion
 @echo off
 REM It only takes two or three minutes to do a full install, so for simplicity we do that.
 REM it is installed using xcopy /d, so if it hasn't changed then it doesn't do anything.
 
-set PYTHON_KITS_PATH=p:\Kits$\CompGroup\ICP\genie_python_3\
-set PYTHON_INSTALL_DIR=C:\Instrument\Apps\Python3
+set "PYTHON_KITS_PATH=\\isis.cclrc.ac.uk\inst$\Kits$\CompGroup\ICP\genie_python_3"
+set "PYTHON_INSTALL_DIR=C:\Instrument\Apps\Python3"
 
 @echo Updating genie_python
 
-@echo Deleting P drive
-net use p: /d
-@echo Mapping P drive
-net use p: \\isis\inst$
-
 if exist "%PYTHON_KITS_PATH%\LATEST_BUILD.txt" (
 	for /f %%i in ( %PYTHON_KITS_PATH%\LATEST_BUILD.txt ) do (
 		@echo NEW_BUILD: %%i
 		call %PYTHON_KITS_PATH%\BUILD-%%i\genie_python_install.bat
-        if %errorlevel% neq 0 goto ERROR
+        if !errorlevel! neq 0 goto ERROR
 	)
 ) else (
 	@echo Could not access LATEST_BUILD.txt