build: fix typo

PR-URL: #13396
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>

vcbuild.bat

@@ -157,7 +157,7 @@ if _%PROCESSOR_ARCHITECTURE%_==_AMD64_ set msvs_host_arch=amd64
 if _%PROCESSOR_ARCHITEW6432%_==_AMD64_ set msvs_host_arch=amd64
 @rem usualy vcvarsall takes an argument: host + '_' + target
 set vcvarsall_arg=%msvs_host_arch%_%target_arch%
-@rem unless both host and taget are x64
+@rem unless both host and target are x64
 if %target_arch%==x64 if %msvs_host_arch%==amd64 set vcvarsall_arg=amd64
 
 @rem Look for Visual Studio 2017