fix typo, patch by Trevor Harmon (PR8537)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118131 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/TestingGuide.html b/docs/TestingGuide.html
index 921069d..3cbcd1a 100644
--- a/docs/TestingGuide.html
+++ b/docs/TestingGuide.html
@@ -237,7 +237,7 @@
 </div>
 
 <p>where <tt>$LLVM_GCC_DIR</tt> is the directory where
-you <em>installed</em> llvm-gcc, not it's src or obj
+you <em>installed</em> llvm-gcc, not its src or obj
 dir. The <tt>--with-llvmgccdir</tt> option assumes that
 the <tt>llvm-gcc-4.2</tt> module was configured with
 <tt>--program-prefix=llvm-</tt>, and therefore that the C and C++