[obj2yaml] - Fix a comment. NFC.

I forgot to address this nit before committing..

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375405 91177308-0d34-0410-b5e6-96231b3b80d8

test/tools/obj2yaml/invalid-section-name.yaml

@@ -1,6 +1,6 @@
 ## Check we do not crash/assert when dumping a broken section name.
 ## Here we replace "foo" name with a sequence of characters that
-## do are not representable as unsigned char.
+## are not representable as unsigned char.
 ## We used to have an assert for this case before. 
 
 # RUN: yaml2obj %s -o %t