Improve ERRORLEVEL handling in the MSVC batch build tool sub-routine 'fn_UnsetVariable'.

FossilOrigin-Name: fe123ab4f17f97ba9d64a7e0589ac47fd9d43877

manifest

@@ -1,5 +1,5 @@
-C Another\ssmall\stweak\sto\sthe\sMSVC\sbatch\sbuild\stool.
-D 2016-02-05T04:39:11.238
+C Improve\sERRORLEVEL\shandling\sin\sthe\sMSVC\sbatch\sbuild\stool\ssub-routine\s'fn_UnsetVariable'.
+D 2016-02-05T04:55:01.668
 F Makefile.in 027c1603f255390c43a426671055a31c0a65fdb4
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 72b7858f02017611c3ac1ddc965251017fed0845
@@ -1367,7 +1367,7 @@ F test/zerodamage.test cf6748bad89553cc1632be51a6f54e487e4039ac
 F tool/GetFile.cs a15e08acb5dd7539b75ba23501581d7c2b462cb5
 F tool/GetTclKit.bat 629d87562e0487c386db630033931d12d62e6372
 F tool/addopcodes.tcl 4ca9c3ef196f08da30add5d07ce0c9458dc8c633
-F tool/build-all-msvc.bat 8686ace11a70a2dcd25d8a32e594517040402f1d x
+F tool/build-all-msvc.bat 31866578036cd1d962628059b0760d407c3ce4d8 x
 F tool/build-shell.sh 950f47c6174f1eea171319438b93ba67ff5bf367
 F tool/cg_anno.tcl 692ce4b8693d59e3a3de77ca97f4139ecfa641b0 x
 F tool/checkSpacing.c 810e51703529a204fc4e1eb060e9ab663e3c06d2
@@ -1426,7 +1426,7 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 42736fb0adc82a0fb692850ff3dd3f9b501cbf1f
-R 42b9a28037cad0e47b316fe911b23a4e
+P 76718bbce775e13a82893be519ddd98b2f3a4942
+R 86ae75673aa5606b4c7ad2944af4b890
 U mistachkin
-Z 608fd16e3704c006125d3c0da336963e
+Z b9861f56ee1885b232be909ed448816a

manifest.uuid

@@ -1 +1 @@
-76718bbce775e13a82893be519ddd98b2f3a4942
+fe123ab4f17f97ba9d64a7e0589ac47fd9d43877

tool/build-all-msvc.bat

@@ -735,10 +735,10 @@ GOTO no_errors
     SET VALUE=
     ENDLOCAL
     SET %VALUE%=
-    CALL :fn_ResetErrorLevel
   ) ELSE (
     ENDLOCAL
   )
+  CALL :fn_ResetErrorLevel
   GOTO :EOF
 
 :fn_AppendVariable