Fix the build when a different version of Qt is in PATH

When we add our Qt to PATH, prepend it so that it will be found first.

Change-Id: I405496d6a08d676b5a2e0d9bd792de7ba9abe7f9
Reviewed-on: https://code.wireshark.org/review/18988
Petri-Dish: Graham Bloice <graham.bloice@trihedral.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Graham Bloice <graham.bloice@trihedral.com>

CMakeLists.txt

@@ -2008,7 +2008,7 @@ if(BUILD_wireshark AND QT_FOUND)
 			# be smart enough to copy debug DLLs when needed.
 			add_custom_command(TARGET copy_qt_dlls
 				POST_BUILD
-				COMMAND set "PATH=%PATH%;${QT_BIN_PATH}"
+				COMMAND set "PATH=${QT_BIN_PATH};%PATH%"
 				COMMAND "${QT_WINDEPLOYQT_EXECUTABLE}"
 					$<$<CONFIG:Debug>:--debug>
 					$<$<NOT:$<CONFIG:Debug>>:--release>

packaging/nsis/CMakeLists.txt

@@ -196,7 +196,7 @@ macro( ADD_NSIS_PACKAGE_TARGET )
 
 	# qt-dll-manifest.nsh. Created using Wireshark.exe.
 	add_custom_command(OUTPUT ${_nsis_binary_dir}/qt-dll-manifest.nsh
-		COMMAND set "PATH=%PATH%;${QT_BIN_PATH}"
+		COMMAND set "PATH=${QT_BIN_PATH};%PATH%"
 		COMMAND ${POWERSHELL_COMMAND} "${_nsis_source_dir}/windeployqt-to-nsis.ps1"
 			-Executable $<TARGET_FILE:wireshark>
 			-FilePath ${_nsis_binary_dir}/qt-dll-manifest.nsh

packaging/wix/CMakeLists.txt

@@ -334,7 +334,7 @@ macro( ADD_WIX_PACKAGE_TARGET )
 
 	# QtDependentComponents.wxs. Created using Wireshark.exe.
 	add_custom_command(OUTPUT ${_wix_binary_dir}/QtDependentComponents.wxs
-		COMMAND set "PATH=%PATH%;${QT_BIN_PATH}"
+		COMMAND set "PATH=${QT_BIN_PATH};%PATH%"
 		COMMAND ${POWERSHELL_COMMAND} "${_wix_source_dir}/windeployqt-to-wix.ps1"
 			-Executable $<TARGET_FILE:wireshark>
 			-FilePath ${_wix_binary_dir}/QtDependentComponents.wxs